I can see that, and even thought about mentioning it. Someone with other Arts combinations can trivially penetrate the magic human's might, kill the person and render their remains for the vis therein. It's not that magi can't kill normal people easily, it's that when they kill magical humans, only when not stripping might, that they get a nice reward for their efforts, too. Magic beings that are sentient should probably know this about the Order, by now. Deal with magi carefully, because they have some motivation to see you dead, more so than a mundane.
They might die. It depends on the circumstances. Losing Magic Might makes a being non-magical. If that is important to survival (ghosts and revenants, for example), then they die. If not, they simply become non-magical. This is handy for an SG so that stripping the Might from a magical kraken, for instance, still leaves a big, angry kraken to deal with.
Still, use 3 points for a Greater Immunity to Might-stripping effects. Now you have 7 left and are more protected from Might-stripping effects than you were at MM15. Also, you're less vulnerable to Acclimation and have a much smaller learning penalty. You have less magic resistance, but if you're with magi and under the protection of Parma Magica, that's not an issue.
Yes, and even better if kept alive and enslaved by a Verditius with the right Mystery Virtue. Enslave them with magic. Strip them down to MM1 for Vis in the lab. Let them Transform to get Improved Might and strip it down for Vis again. Or maybe they could get a fun Power you want and you could take that.
My opinion, is that Magic beings should give up a lot of character agency, they are supposed to be more like the ideal of their species (whatever that means) and they are supposed to be disinterested in the mundane world, generally. Beings with low might probably are more interested in the mundane realm, less like the ideal, but give up some agency in a saga, nonetheless.
If we look at silveroak's character as an example, that character has almost zero agency. His character can't even decide which projects he works on (as a player that's giving up a lot of agency), and it's the troupe as a whole who determine what projects he is assigned to accomplish. Oh, and I expect we will work him more than 2 seasons out of 4...
Well, let's see. Let's note that the ones with Might have a choice about Powers versus Abilities. But let's see how many points it takes to stay on track. They start with the Abilities of a 21-year-old companion. If a companion starts at 31, that's +150 experience, costing 3 Qualities. So, yes, it looks like the Magical one is up by 12 Qualities at start. We can probably safely assume approximately 27 experience per year after the game starts (don't forget the bonus exposure and that Adventure Experience is separate - house rules). So 12x50=27t, or t=22.2. Yes, it would take about 22 years to catch up.
I suppose it would help some if we allowed companions to learn, roughly, as they see fit for those two other seasons. That would raise the annual average slightly. Speaking of which, what happens if a PC teaches a bunch of gross and the PC provides a Source Quality of 15? I would assume that replaces their season of 7 - the PC should get some return out of the investment. If done twice, replacing their season of 7 and their season of 4, most likely.
Yes. I'd actually voiced concern over this on his development thread. I was afraid he'd given up so much agency it wouldn't be fun to play the character, being too close to playing a piece of lab equipment.
Do we have any guidance or limitations on building familiars? For example, what season and Might are they? Are they allowed to take Educated/Arcane Lore to get otherwise inaccessible skills, or must those be learned in the course of play? Do they have their Might learning limitations ignored when they're studying with their master? That sort of thing.
When I put Realms of Power: Magic on the approved-for-use list, I had intended it to be for familiars (and magical creatures) only, and thought I had put that clarification on there. Turns out it was on the Stonehenge wiki. But I will be adding it to this saga's Chargen page, too. Making a magical human companion is too easy to make something ROP, which I don't want to go through again.
Speaking of the Character Generation and Advancement page... 
Advancement for familiars is handled according to the rules in the MRB. They aren't penalized by their Might, and they "can learn Abilities in the same way as humans".
By the way, I'm shunting the discussion on Gifted Companions into its own thread with a poll.
As you wish.
Can a companion undergo initiations before the start? UnGifted Gragachan advancement are based on scripts (HM pg 62) May he take those in his years of advancement?
I would think so as that's how you make an unGifted hedge mage. You just pay your points for the Virtues and make sure you select Flaws you would have gotten during initiations. That's what I did with Rónán, which is why he has about 15 points of Flaws without nearly that many points Virtues. A bunch of the Flaws are fitting for the initiations and would cause penalties. But the later initiation effectively trumps lots of them and makes them not really Flaws anymore. So I counted them as 0 points instead of taking value for them; after all, if it doesn't penalize it's not a Flaw.
This.
In Heviz, I had a character with a minor magical focus (counterspells). I was wondering if that would be possible here in this saga. mMf(counterspells) would apply to the PeVi Unraveling spells, both in casting and learning/invention. IT would apply at casting if it is a direct counter to another spell, for example Mighty Torrent of Water against Pilum of Fire or BAll of Abysmal Flame. It wouldn't apply to spells like Wizard's Leap and the like, it must be a direct counter to another spell.
Ooh. Laerlegger and Beatrix are going to get along! One with a focus in corpses and another with a focus in human bones who carves human bones. And neither likely as creepy as Hope's familiar! No wonder we all went to the edge of Europe!
Sounds valid to me. Minor magic focus applies to sponts, too, right?
Yeah, to sponts, they are spells. The idea is that she's good at shutting down someone's magic to allow the grogs to get the grogs into position for lethal kills.
Can we pick invested devices as part of the 75 pts BP we have personally? Or is that too much like getting free stuff?
Yes you may. 2 build points per 5 points of Effect.