Alright then: Indeed for 2v2 and FFA this map should do fine. All basics look good.
1-For 1v1 I would adviase against using bases/expansions that only have a single entrance/exit, but for other gamemodes it is much less important. Same goes for the northrend merc camps. The usual notes:
2-At the top left starting position, there seems to be one skeleton too many.
3-Many creepspots are very similar, this might be becuase of the maps story. However, I would at least not make the starting positions and nearby goldmines are 100% identic ( even thought in 2v2 or FFA the starting positions wont have creeps).
4-No AoW creeping possible.
5-Cant build farms or place wisp near merccamp. Not that important though, as they wont be taken in earlygame.
6-The ramps to the small camps in the exact north and south are very small.
It is a good work. If you have the time, you can try to make a 24 player now, as people have already started playing a few fun 24 player FFAs on the PTR on a modified (and not in good way) blizzard map. There are n real maps for more than 12 players yet, and the first acceptable map will surely be played a lot on the PTR. I've already starting working on one myself, but I'm not sure how fast I can finish it, so you might beat me