I'm sure FMA could be renovated, but the bones are so old I don't know if it would add more costs to shore up than would be worth it. I think that's why Bama just started with the idea of a brand new building.
I do think Colonial Life could make some significant changes, but you'd have to gut portions on the inside to move things closer to the action. I think there could be some design elements taken from Ok State and Auburn's arenas (with the pit-like element) - or even the club section at little john.
It's unfortunate that USC built that when they did. I feel like it was one of the last characterless, mega-arenas built and then there was a shift to smaller, more intimate arenas that were more geared toward fan experience.