Your mix is far more ambient and verby than I typically do, so I find it a bit hard to really know where to recommend changes. I certainly go for a much more straight forward sound. The hall verb dominates the vocals so completely in the verses and pre-chorus, I certainly would be using that as a parallel effect and probably be using side-chain compression to squash the reverb tails until the vocal cuts out. You did manage to keep them in front though largely out front. The verb effects get much smaller in mono.
The contrast of how out front (and loud) the vocals get going into the chorus is very distracting for me. Especially in mono.
In your bridge, the harmony vocals sometimes come to the front - sounding closer and in a couple spots louder than the main vocal.
Drum treatment is very 80's which suits the other vibe. You did a good job automating them too. But I miss the percussive samples in the second verse...
Yeah, I guess because you've taken a creative path different from my norm, my general advice probably comes across as "don't do it!". And that's not great advice at all! I think the biggest, real constructive bit of advice is to make sure that the vocal levels don't jump so dramatically going into the chorus.
Stick to your guns!