1. If I don't release the charging handle cleanly, the bolt doesn't go into full battery. Since there is no forward assist, I would try pulling the charging handle back a little and re-releasing... sometimes it would work & sometimes it would push another round in under the one already chambered. Possibly a break-in issue that would clear up after some use, possibly a training issue that would clear up after some practice. Regardless, I've decided that this is fine for a bench rest rifle, but it isn't an issue I want present on a tactical rifle. Solution: change uppers to one with the built in FA and ejection port cover.
This is not necessary, let that thing slam home, you're not helping anything by doing that.
Welcome to the forum, good luck, but don't try to fix that barrel, it's nothing but a bat now. DPMS should take care of that, it's pretty unusual.