I had lots of fun on this map, but there were very many things to complain about. It's not really worthy of being called a release candidate yet, so beware of tons of nitpicking (and serious issues):
First: Clipping, man! CLIPPING!

It's very important that you improve it for the next release - after all, it's rc! Just look at what FLOOR_MASTER said; lots of those errors were still there.
Pretty much all your spawn doors are messed up. Check them and compare their inputs to those of Valve's maps. It was hard to get out of spawn when multiple people were ganging up to get out.
I really like the theme. The map looks beatiful - well done on that. However, a very bad thing is that the theme is so neutral. It's not all your fault - put in a lot of rocks and dirt, and it's hard to emphasise team colours. Still, you have to improve a few things, because I ran back to our own first spawn from the middle. Twice. For example, try to avoid making this sign switch skins when the cap is taken:
See? This is RED's territory, but the big B just screams BLU, regardless of the RED-themed skybox and wood.
The map is also very open. In many cases it's ok, but look at this...
Longest potentional Sniper line I've ever seen.
I think the lighting is a bit off compared to the sky. It's a dark sky, but I see lots of sunlight on the ground. And why is your fog green?