House and setting rules

Right. The example I have been looking at was Hugh, not yours.

Hugh is honestly a bit of a mess- he is from Normandy with an Irish faerie for a familiar, which came from several disjointed conversations and I was caught up in the timeline of his initiations and missed the fact he hadn't set aside time to recruit his familiar, which had only been addressed as being an acceptable familiar not when and where he found it... I probably should not have approved the familiar given those situations.

OK. Is Magical Animal Companion the only way to start game with a familiar? Or is it possible to spend a p/g season to find one?

One or more seasons, depending on what you are looking for and where...
a bear or snake of virtue, for example, would be far easier to find in the Rhine than Hibernia...

I was thinking of maybe a Raven of Virtue, if that is bindable with InVi (or ReCo, but InVi sounds more likeliy). What do you say, is a Raven of Virtue in Novgorod a one-season search?

Balder is quite open-minded ... if he finds an animal he connects with ... meta-gamingly one should be looking for a creature with Int, which the canon raven of virtue has.

Does this also count for Cautious with (Ability)?

yes, should have mentioned that on the character thread but other issues being considered and accepted took precedence (primarily the suitability of Atlantian Magic...

Warping is tallied separately depending on realm. Any source of warping may trigger twilight (or other tradition based reactions), and warping from twilight is always magical.
Rolls to avoid twilight are based on the sum of the warping scores, rolls to comprehend twilight depend only on the magical warping.
Holy characters subtract any infernal warping score from their divine warping for calculating holy ascent.
Similarly Vituperation requires rolling against the sum of all warping to avoid negative affects, but the roll to avoid aging is based on their infernal warping minus their divine warping, as those who are divinely warped are given more of a chance towards repentance by heaven.
Faerie sympathies depend wholly on faerie warping alone, while faerie metamorphosis will create a glamor associated with each realm- and of corresponding nature- an infernal glamour will always be villainous, a divine glamour will always be virtuous or noble, a magical glamour will always be mysterious and alien, while a faerie glamour will be a typically faerie glamour.
Acting during a faerie calling requires rolling against the sum of all warping, but resolving the episode requires rolling against faerie warping alone.

Does source mean realm here? Or may there be different sources of the same realm?

magic items impacts: I am not going to go strictly by levels for calculating impacts of enchanted items on labs and economics- they will be sued as a guideline but not a determination for labs, but for economics I would rather calculate the realistic impact, with limits applied similar to hiring specialists to reduce costs.

a magic being which cannot find an aura strong enough to support their might without acclimation may reduce the reuirements by other methods (especially vis consumption) by remaining in a weaker aura and only having effects or vis to support that portion of their might which an aura does not effect, and effects which divide their effective might for calculation are applied to other support processes.
So a Might 80 dragon sleeping (magical meditation) aside from a few days a year in a level 3 aura would be supported as a might 40 creature with 15 might supported by the aura, requiring a consumption of 13 pawns of vis a year.
The maximum sum of all preternatural tethers is 5, so the above dragon could then raise a natural aura to 8 or a preternatural aura to 5 after one year, and then support itself by either remaining in magical meditation (aura 8) or with a still lower cost of vis for a lesser aura.

familiar's and learning: SQ for bound familiars learning mundane (including arcane) abilities is not reduced by their might. Experience towards transformation is.

regarding Feral upbringing- I see this as a core rule, not house rule, but it has come up several times- a character who has this flaw has no language abilities, and is not familiar with civilized society. Period. Someone who used to have this flaw at some point in the past does not have the flaw now, and should not take the flaw to represent a problem that they used to have.

Recently asked and answered- Lab bonuses in an art (not GQ or other specializations) will add to the study of that art when studying vis in that lab.

In light of this house rule on books:

is "writing" or "books" an acceptable specialty for Teaching?

yes

Taking this by the letter, it seems that one can, say, start from 0 and read a L5Q15 summa, apply the full 15xp (score 5 which the summa permits) and then, afterwards, multiply by 1½ to get 22½ xp (score 6). Is that the intention?

It’s my understanding that even with affinities applied to books and teaching sources are limited to raising the ability to the source level so a L5Q15 summa can only ever give 15xp.

Quite likely, I read house rules as the Devil reads the Bible.

The limit applies, as nullsetting stated, before points are applied: so you would read the summae for 15xp, multiply by 1.5 for 22.5 points, then apply the limit of level to bring it back to 15xp.

advancing children created by someone else: they are going to start where they are at, but when the penalties change due to aging I will allow you to shift stats by either not increasing a stat (lowering the base stat by one) or by increasing it double the regular amount(increasing the base stat by one)- the accounting must balance but traits like improved characteristics and balancing flaws (or the other way around) may be taken as childhood traits as they grow through that phase. Note- this special advancement rule is only available for advancing grog children into companion adults when the grog child was made by someone else