Okay, this map is full of problems, with little good associated with it. To begin:

1) There is no (clear) middle of the map. In some cases this is fine, however for this map, the lack of a middle makes the map feel disjointed and unorganised. Not to mention, the bomb sites are directly affected by this also, no connectors that are viable.

2) The bomb sites are bland and generic. A lack of cover, and some times, too much cover in places makes the map look unprofessional and most importantly, boring.

3) The visual aesthetics of the map are bleached of colour. Add in some colourful props to introduce visual diversity in your levels.

4) Too many doors, and some are not obvious you can open and visa versa.

5) The scaling of the level; some places are too open, some to cramped.

Advice: I would say, redesign the level. Extremely vague, however: start by redesigning the bombsites, and no offence - make them interesting, reduce the amount of corridors and completely re-haul mid into something like existing maps, then change the visuals of the map (colour) and finally, work on the timings of the level - I dislike how the B bombsite is next to CT spawn. I know what I have said is negative, however, see it as constructive criticism to improve on your map. Thanks.