I don't think it's out of character for AA to be comfortable hugging a romanced player. Maybe a different animation as to what Spawn has but being able to hug him doesn't feel out of character to me. I definitely think an option to hug AA would be nice, as well as options to kiss both UA and AA in their romanced epilogues.
I agree and thanks for the examples. Another line when he talks about being in each other's arms is when you question him about "flourishing": 'Look at us. We share a palace, share power, live lives eternal in each other's arms. What more could anyone want?'
I qoute everything you said! I should say that I've never felt so much the need to hug AA during the final party, as this phrase that says "I have power but it would be nothing without you. You complete me" is worth more than a thousand hugs to me. Of course, a hug would be the icing on the cake to crown the moment... Even better would be a kiss! Otherwise I thought: what would you say about a hand kiss? The TAV that takes Astarion's hand and kisses it as a sign of affection and devotion? A sort of reference at the night which Astarion transforms the TAV.
Another line when he talks about being in each other's arms is when you question him about "flourishing": 
