Not to beat a dead horse, but the map is HUGE.
When a map is this big, it nullifies anything that:
Heavys, engineers, and pyros can do. It also makes snipers horribly OP.
I think that the scale may be OK if you shrunk the yard area hugely, but left the last point zone just a bit shrunken. You also need more ways to the last point, possibly a top route.