Looks quite good. The only thing I have to say is that the entrances looks a bit narrow.
[sub]Hows pathfinding with that middle expo?[/sub]
Fine... I don't see why there would be anything wrong with it.
ADDITION:
I played a few games on the map... and admitedly, it seems very imbalanced. Ah well.
Haha.
I didnt think the idea was terrible, maybe try it again on a different tileset (unless absolutly neccesary), and open it more by the back door and 3/9 expos. Maybe that will add more room for a closer 2nd expo besides mid.