Looks pretty good. This might just have the right balance of speed and strategy to make it popular for both public servers and matches. I'm trying to standardize using the "pball/maps/beta" directory for beta maps to reduce map directory clutter, so if you could use that next time, it would help (the demo uses maps/cmtns_beta1). For the final name, might I suggest "carpathian.bsp"? For some reason, cmtns is harder to remember, even though it's shorter. "Was it cmtn.bsp? cmountain? Something like that..." Plus "carpathian" looks like a real name instead of 5 random letters.
I've got it up on the beta server for testing: paintball2://216.127.68.86:27919
As for removing the sky "wallhack", that was just a quick fix. I could take some time and make it look nicer if you'd like. Also, I'd personally make the flags worth less (like maybe 3 points) for the simple reason of making the matches last longer. Castle1 matches never seem to last long, and from the looks of it, grabs/caps are even faster in this map.