Hrm. I was afraid the first post wasn't going to cover the full story here. Guess I should respond to things.
This release is (and always was) intended to be a
public beta, not a release candidate. There are still a few areas that could use some fixing up and there haven't been any proper full playthroughs aside from what I've done (and prolly Torm too). There should've been more indication that the first few players are gonna be a guinea pig audience of sorts.
All testing and development was done on ZDoom 2.6.1, so I'm not sure what the deal with the grenade issues is. I've also never seen the "bosses die" thing happen at all, so that's another bug related to something different in SVN. The tl;dr is that it's probably best to stick to 2.6.1, to avoid whatever's causing the weirdness there.
Caught a few actual issues though already. Need to figure out a way to detect when a player picks up the chaingun from a dropped enemy; that message display slipped my mind somehow.
[EDIT] I should also mention that the way for displaying the code (you'll know it when you see it) is also silly and needs changing. Basically a placeholder that hasn't been filled yet.