they just hang out in their abandoned coffee shop and talk about overthrowing hero society. or at least, most of them do, because ryuga is usually training somewhere and tsubasa is plotting subterfuge.
"Working with Tamara was heart-work. Every decision we made on set was to ensure our Hawk family was filled with love despite the hardships of our characters." - Morningstar Angeline
Do you think he fidgets when he's nervous? It might not be as often as in cannon, but do you think he does?
In my headcanon, Dark Ace paces. A lot. He doesn't have to be nervous, the man has a lot of restless energy and if he's not able to get rid of it by exercising or beating the hell out of a sky knight or helpless training dummy, he'll pace.
A specifically nervous habit that he has, but doesn't develop until later in the show for my own take on it, is fidgeting with a wirework bracelet he wears under one of the cuffs on his armour. It's shaped like a dragon and was gifted to him by a close friend on Cyclonia. If he's worried about something, he'll mess with that and make sure it's still there.
I know there are various ways to interpret the word the strongest in this case - I guess, interpret it however you like. The strongest as the most useful on the battlefield, the strongest as having the most magical power, the strongest as the most likely to survive anything, it's up to you.
**Obviously did not include Solas, he has certain shall I say advantages that would make any comparison unfair. Technically some of our friends have additional passengers (Anders and Wynne) but the games have shown that they still can be relatively easily defeated, somehow I do not feel like this will be the case with Solas.