Wow! I played this map yesterday on the EU server and I was astonished by the great layout of the map! Specially the middle, it's one of the best middlecaps I've ever seen! :O
The routes leading directly to the middle need some cover between eachother, now when you choose that path and face resistance like a sniper or spam you really are forced to either go back, up the to the enemies bridge or rush into the middle to have a chance for survival. A big rock (like yukon uses for cover) or a plank to cover for snipers and other enemies on the ground would help strengthen that position a bit but still not too much. And at the same time add some terrain a good player can use in the fight for the middle (because right now it's rather plain on the ground)
Also the "beam" over the bridge(s) looks like it's be either playerclipped or jumpable by the looks of it. But when I tried I noticed it was neither, using a push-brush to keep people away may sound like a good solution in theory but when in gameplay it's really not, it adds confusion and it doesn't look good when you gets pushed by an invisible. And that you can stay on there by just walking in the other direction doesn't make it any better. I think you should either remove it or do it the traditional way.
What I really like about the middlepoint is the range between the 2 bridges, wether u meant it or not it's precisly the right length for rocketjumps and scouts with FAN (triple jump) to reach the other bridge and I think that's perfect.
The second point has a good layout too but it is way to open, a good sniper can perish a defence by from the upper route. My suggestions:
1.
http://files2.bredband.net/cpuser_b298987/tf/cp_stark_a50000.jpg
The idea of having cover there is to force the sniper or any player to get closer and also to loose height, to make him easier to reach for the defenders.
2.
http://files2.bredband.net/cpuser_b298987/tf/cp_stark_a50002.jpg
This cover is just to limit the sight for a sniper to ease things up for defenders.
Also I marked the ledge simply because it looks wierd to have a big ledge there just to playerclip it
Just out of curiosity, what on earth is the big rooflike thing (seen in pic 1) suposed to be?
The third and last point is pretty much, the only thing I can think of is
http://files2.bredband.net/cpuser_b298987/tf/cp_stark_a50005.jpg (yes it's supposed to be a rock) to limit the sight for attackers.
On a side note I've looked at this from a perspective of competitive play and not at all what's good for it on a 32-server.