OK, so after playing on this for 5 hours, I have some useful input:
1) I'm not a terrific spy, yet I was doing very well...why? Because of the height advantage. Batman doesn't just walk up to his opponents, he flies down from above. I propose putting some awnings or some roofs that extend outward to make some of the visibility from the top to bottom cluttered so that it's harder to batman stab people.
2) Health kits: while something not taboo in arena, 5 may be slightly too much. Recommend removing the ones underneath the stair case, as they are too easy to get. Put some risk in: Oh you want health? Well you're gonna have to go to the middle to get it.
3) Your flanking routes are amazing.
4) Don't forget to wear your hardhat.