Out of bounds areas are sometimes hard to recognize. There's three areas that are especially bad and people try to jump to: The graveyard (extending the wooden fence to all the way along the cliff would work), the gravekeeper's shack (the hiding thing before B, it has a huge gap between the tyres and the wooden planks, making it seem like you can go there), and the roof left of A, seen from RED's side, as there's a ladder on it that makes it seem like you should be able to play around on there.
That said, these are minor things and could be tweaked afterwards if needed.
One personal thing is the R logo and the skulls, I think they leave little open to interpretation and aren't stylistically as fitting in the TF2 universe, might've been better to leave the jars and clocks just in a solid colour and the large flags with a more generic weapon. I guess something like that is up to Valve to decide, though.
Other than those, looks magnificent and real fun, good luck with the contest.