I'm sorry for being honest, but there is actually nothing that was really tf2-ish.
Also, it feels like you tried to put too much player attention on the CP,
the CP is actually unimportant for arena mode,
because it will end up in an 1vs1 duel in 95% of cases anyway.
Just try to create some areas that are fun to play on,
and not just tight hallways with a big room in the middle.
I can't repeat often enough, look at valve maps.
Thats probably half of the mapping magic.
Edit: I was one minute to late. :/
Also, don't take a look at your sketches, they are probably old and bad.
Also my doing a totally ducked up map, you can still learn something.
You should definitely start with a fresh and new layout.