Yes everyone counts. The more there are in, the more power we have. And since it doesn't cost anything until there is a refund it should not be a problem for anyone to join.
The haircut would be much better than the one TF was offering btw.
..so ..yes!

Should those with a single BTC at CL even bother with this?
Winning a judgement, and collecting on a judgement are very different things.
The chances of getting a payment when they don't have it is not very good, if all the wealth this guy has is now gone, you aren't going to get anything with a lawsuit other than a loss on the books for you to claim against taxes and a lot of suffering for everyone.
On the other hand, if TF is a thief and took the coins, then you may get them this way. I just don't think that is the case here. I think he was just overconfident and now is in over his head.
Disclosure: I have 1.08... on CL