This holds for wards using container targets. T: Ind wards in particular can move with their target.
It is not sufficient.
Remember. a courtyard is canonically a T:Room. So I cast a D:Sun, T:Room spell "of type 2" on a courtyard. Not a ward! Say, a ReAn spell to make animals tame and nice. Then, I teleport the four walls of the courtyard 1 mile to the south. Does the spell stay where it was? Does it move with the walls? Does it vanish?
So you have to address, for all containers (in the technical sense of T:Room, Structure, Boundary etc., exactly what happens when the symbolic perimeter of the container moves. I think there is no clear, rigorous answer, just like there is no clear rigorous answer to the question "is a ship still the same ship if I tinker a lot with it?".
The answer depends on how "essential" that concrete object representing the perimeter of the Container is to the Container. The plaster on the outer walls of a courtyard can be easily removed without any T:Room or T:Boundary spell being affected. The same does not hold if the walls of the courtyard move. But in the vast majority of situations, there will be an easy-to-reach consensus.
The title and the OP of this thread talk of Aegides. They are for now T : Boundary.
So you may allow me to consider in this thread just arguments regarding Aegides and rules regarding Boundary targets - and not to anticipate, that your interest goes beyond them also to T: Room. OK?
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No. Because this thread is about stuff that specifically regards the Aegis (on moving Boundaries).
If there's some issue about ... Rego, say, that affects every Rego spell, it should not be addressed in this thread by trying to find an Aegis-specific patch. It should be addressed for all Rego spells, in fact ideally before any Aegis-specific discussion it might have an impact on.
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In that case, you should perhaps just introduce your contribution by an explanation, just why your point of interest is relevant to this thread, instead of with:
OK?
Also, a courtyard can be a lot of targets. e. g. T: Ind, T: Room or T: Boundary.
This might belong to another thread, because you first have to sort out, whether the courtyard - as T: Room - needs to have a floor and you hence destroy it with the teleport of its walls.
Best start with:
So, you decide to teleport the courtyard with both floor and all walls, then the type 2 spell with T: Room might move with it.
Do I have to?
The only "symbolic parameter" among them appears to be the boundary of T: Boundary, which (ArM5 p.113) "affects everything within a well-defined natural or man-made boundary". By (ArM5 p.135f) The Bountyful Feast, such a boundary can be a set of property markers or even property deeds.
Does selling/buying new property then change the boundary of the area, as soon as it is documented?
EDIT: Could then a canny magus, whose covenant's Aegis is linked to the deed of its area, just buy the land another covenant is built on from its rightful owner, then destroy that other covenant's Aegis with a Wand of assault, and at nearly the same time perform the last stroke of the deed joining that other covenant's land to his own covenant's? Would at this monent the other covenant's Aegis be replaced by that of the canny magus' covenant? 
I think you ask what it is you want the end result to be.
Now, I would like it if covenants that inhabit ships and caravans are as well protected as those sitting on bedrock.
And therefore I'd say that no Aegis may penetrate another. The moving Aegis will just bounce. If I wanted to be doubly sure I'd say that they can't even approach another Aegis closer than a couple of miles.
The spell isn't well understood or reconciled to Hermetic Theory. It can be as quirky as we need it to be.
I'd also argue for a minimum size of Aegis larger than that which can be carried as a personal item.
I'm sure that in this great mass of speculation there are reasons why this Cannot Possibly Be but I ask the story based question again. Do you want it to be possible for there to be a mobile Aegis? If so don't bring up world wrecking possibilities. There are enough means for the Magi to break the world already.
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If we can distance ourselves from just errataing in a mobile Aegis, we may be able to introduce sufficient rules to have a mobile Aegis in some sagas, based on new Ars Magica 5 contents.
We need some new rules. Perhaps around a new Target replacing T: Boundary in a variant Aegis, which is not accessible to just anybody and brings its own limitations. Or a way to enchant an Aegis into a vessel, thus turning it into an enchanted device and thereby invoking all the limits on expanding and disassembling it.
So I am speculating about a new Legend of Hermes. A seafaring follower of Notatus and Seeker of the wisdom of Atlantis, now buried with their vessel at the bottom of the sea.
There is a legend about a variant Aegis protecting it! But where is it sunk, and what remains of it? What did its creator find on its last voyage?
There may be whispers, that our Seeker found the pre-Hermetic mystery of the protections of the Paralus, studied them, incorporated them into their own vessel and then embarked onto its last voyage.
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The Aegis of Assault has horrible aesthetics, and should not be possible for that reason.
I'd note that warding a ship against water would stop you taking drinking water aboard; better make it a bit more specific. And be prepared for the Warping.
There is more story potential in @OneShot's idea of characters trying to create a Aegis they can use with their ship-based covenant than there is in simply saying that it is already possible.
Another bit of bad aesthetics: Wards do not exert force, so a circle ward passing over someone does not move them. However, if you can drop it over them, as if this were some sort of hoopla stand, they cannot leave. There are easier ways to paralyse someone, so this is not a balance problem, but, as I say, I really don't like the aesthetics.
Mind you, I'm not really fond of the aesthetics of orphaned Aegides floating in space…
I feel that something like this is correct. We don't necessarily need anything more precise than that; we have coped without for 17 years, after all.
Still thinking about this.
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There are, I think, two elements to this-
- the fence represents the perimeter, but is not the perimeter
- magic is all about symbolism.
As such you should be able to alter the fence to alter the perimeter (perhaps with a ReVi spell involved), but it should not allow you to simply pick up the fence and redefine the boundary.
The other thing I keep having images of is ancient (like ancient Greece) naval battles which consisted primarily of ramming two ships into each other until one of them breaks.
If we go by this (and I'm not opposed to this), anything crossing a ring/circle, breaks it.
Yes, that explicitly includes a blade of grass falling across the line.
That is a traditional way of symbolically 'cutting' a magic circle.
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How much it takes to break a circle is very much YSMV and the exact amount is in general better not hard defined. Some groups like playing with 'a speck of sand is enough' and others go to the opposite 'the material of the circle must be physically broken'.
While I have never played in a game that went with the speck of sand approach, I have played in ones that range from just covering the width of the circle in one area is enough all the way through having to actually destroy enough of the circle so that there is a gap in it (no matter how small).
Any change to core after this long a time that sets exactly how much is required to break a circle will break many games and cause an explosion of HR to allow groups to continue playing the way they prefer rather than meaningfully clarifying things.
I would support the blade of grass provided it was done by intent rather than by accident, or if it happened after the passage of a year (for the classic tale of a demon trapped in a circle until some freak occurrence broke the circle after a very long time)
And that is perfectly alright if that is how your group wants to play it. However it is not how every group wants to.
I am just pushing that it should be something that should be up to individual groups rather than some errata that most will never see or use. How to handle what breaks a circle should be up to each group.
I would tend to concur, but if so, it should probably be made explicit that this is saga dependent, and that all existing material is compatible with the entire spectrum of "rigour". I.e. you should explicitly define it as undefined 
Indipendently, I also think that one extreme aspect should be made explicit: that crossing the Circle does not necessarily break it.
My current group is middle of the road. We require that something completely cover the width of circle to "break" it. Also physical damage to a section of the circle can "break" it, though exactly how much was not defined to give the SG some degree of freedom.
So for example in my group, a speck of sand would not "break" a circle. A blade of grass also would not, unless it was large enough and landed exactly where it covered the drawn width of the circle. Circles with a thicker "body" are harder to accidentally break in our game. We also allow people to walk in and out of the circle without breaking it (as long as they are not warded by it and do not step on it).
Our version lends a flavor that our group likes (or at least does not care about). If our current game were to end and we started a new one, we might (Ok, most likely would) play with a totally different way to break a circle.
I think the more fundamental question is the degree to which magic is ruled by symbolism vs. intent vs. absolute rules.
I'm not sure this is absolutely true. I mean, is there more story potential in saying that the Aegis only works on Durenmar, and the characters are trying to replicate it on their covenant?
The question is whether you want your stories to focus on achieving that effect (in which case, yes, there's obviously more story potential) or whether you want to use that effect to enable stories focusing on other stuff (in which case there's obviously less story potential).
See now why usque ad sidera usque ad infera circles are useful ?
More seriously, I agree with the poor aesthetics. But I do not believe they belong to Wards as "paralyzation attacks".
They belong to mobile Circles used as hooplas to carry effects. Those are ugly (when they are not comical: I can see a Flambeau wanting too show of his mastery of both the school of the Founder and that of Vilano tossing hooplas-of-flame over enemies).
Wards used to entrap enemies are ok. I mean, trick a demon into an iron box, and ward that. Even ... create a big iron box around the demon, and then ward that, is not bad.
I would argue that this is also Saga dependent.
Though I would think 'absolute rules' are the least supported, since no two Magi learn or use the same spell. Magus A's version of a spell is different from Magus B's version. That and a few other points make me personally learn towards 'intent'. Support for 'symbolism' shows up most clearly in the mystery cults.