Change æ in italic
The a (and å) are two-storied in roman and change to single-story in italic. Excellent! But I think the a-part of the æ should change in the same way – like in this random clarendonesque font I found on the internet. (Please put this on the to-do-list after the small caps Æ!)

That's not universal, it's a design decision.
The little bit sticking up is ugly IMO and hard to deal with at heavy weights, I usually avoid doing that in my fonts.
Here's another random font that does it as does Besley:

But ultimately up to Owen
You are right, it is a decision. I my opinion it should change in the same way as the a's, and I do not think the little bit is ugly – that may be because i see a lot of æ's all the time (it is in my native language).
On the other hand: it is not my decision,either, just a suggestion.