One other thing to be noted, The fact that both spawn rooms are on the east side of the map. This makes that west route very isolated. Might i suggest moving the blue spawn and flag area to the south west corner? This would create a more symmetrical and even map. However, it might make it more interesting to have that isolated west passage. IDK, but it is something to think about.
Edit: I got to thinking about this layout and I wondered if maybe adding a fourth route to the east could maybe even out the map a bit. I took a minute and sketched out what i was thinking using MS paint and your original layout. You can take it or leave it but I just wanted to try and help.