As long as you give proper credits to Wildfire Games and respect CC BY SA 3.0 you're in the clear

Reducing hitboxes might solve the issue with the wider path from your first video, but the narrow one would remain. It's like chasing the issue. I think hitbox shape might be more determinant: in tight spaces, vertices complicate rotating and straight sides give too much front for static equilibrium. Maybe elliptical shapes with increased on-center repulsion range to avoid compact tiling might be worth a try (since that seems to be the only problem about them, for now).

What color do you imagine it to be? I can imagine the Celtic's color, I don't know why, apart from the obvious.  The Greek letter in one color(yellow or Orange)  and the rest in other colors including green.

right click on no formation to make it the default bro

OK, thanks I'll send him an email. Who should I ask about using assets from 0AD Cheers, Boston