It really shows that this was originally an ongoing webcomic: so many of the plotlines weren't built up well(Charlie's detailed mental issues) some felt like they came out of the blue(Charlie's parents/mum) or barely mentioned(Elle's Egyptian heritage). 
Important topics were brought up but they ended up feeling too much and not explored as thoroughly as they should've been. I understand that's also because of the medium; still I believe A.O. has bitten off more than they could chew. 

Another thing is that this volume (and some of the 3rd as well) are so tonally different from the beginning of the series, it sorta felt alienating...