The vocals fight a little bit, so another approach might be to clone the best track and do a bit of delay that is varied from 20 ms to 10ms and back again. Just a thought. You're on the right track, though.
More bass, really? That's one thing I'm never sure of.... is there a "metered" way of knowing how much bass to use? Like..... "make sure the bass and kick are -6 on the master buss peak meter" or some kind of general rule of thumb ??
Also - yeah, I blame all the drum issues on the actual Roland TD-6 kit.
The drummer, which happens to be a chick in this case, is excellent.... so it's not her..... it's the Roland Drums misfiring.
I've got songs with her on acoustic kits, and she's very good.