Didn't like this at all I'm afraid. Which means, heaven help us all, it's... constructive criticism time!
This is what is known in the trade as a 'box map'. Basically you've started by making a big hollow cube (well OK, cuboid) and then put all your other stuff inside it. If you start from a box you kind of cripple your layout right from the start. In this case you've ended up with a hugely open arena where traversing much of the play area is suicidal, even if you start on full health, and even if you are bunnyhopping like a mofo. There's no way to move around anywhere except the ground without being under constant fire from all over the map. The open layout also means the game fequently picks spawn points that are in plain view so bad guys pop out of nowhere in front of you.
Generally, maps for pretty much any gametype work better if they are divided up into distinctive areas to allow for cover, concealment and evasion. These can be thought of as smaller boxes joined together, because that's generally how you'll build them.
Visually, the structures you have built in the map don't make sense. They have 'real' textures on them but it doesn't seem like believable architecture. Many of the long catwalks/platforms don't seem to have adequate supports. Lots of them cut right across windows on the outer walls. Textures are tiled across massive areas without interruption or variation. Scale is way off in places, some of those containers are the size of a house. Some of your ramps don't align properly to their connected platforms at the ends, if you aren't doing it then working on a consistent set of grid sizes for structural elements as much as possible makes keeping things together a lot easier. Some of your interiors are too cluttered to be easily navigable.
Lights seem to have been placed sporadically - many parts of the map are really too dark. In lots of places you can see definite pools of light where you have placed a light entity, but there is no visible source for that light to be coming from. Try to place light fittings, burning barrels etc. in areas that need to have light in them to avoid the artificial look that unsourced lights give.
You haven't built your cubemaps. You need to load the compiled BSP in the game and type "buildcubemaps" in the console, preferably after placing some env_cubemap entities. The sample maps in the SDK will give you an idea of how to place them.
Sorry if this post feels a bit like an impudent boot applied forcefully to the soft bits, but to me this isn't a release quality map. That said, it's easy to see that you have learnt a lot about the tools while making it as lots of stuff is working as it should, there's probably stuff you've found out that I haven't learnt yet (even though I've been mapping for years I'm new to Source and Hammer). Keep plugging away at it, and good luck with your next map.