RE: carbon arrows, epoxy removal
You're dealing with carbon arrows now and they are a different beast than your good ol' 2117's.
While most all you hear about with carbons is how wonderful and light and fast they are, they do have issues. One issue is they aren't anywhere near as easy to work with as aluminum. With aluminum you just heat 'em up, melt the adhesive and remove the inserts. Not carbon!
Carbons are made with carbon fabric and thermoset resin glue. You can't heat 'em up enough to melt the epoxy without melting the shaft as well. Once you epoxy inserts in 'em, they're done. There is no easy way to get them out and, even if you do manage that feat, there's no way in the world to get the epoxy out of the shafts.
Oh, if you're really, really careful and apply heat to the field point only, to slowly heat the insert a little at a time, and constantly check to see if it's heated enough to come out, then you can remove inserts without damaging the shaft... or so they say. I've been able to do it a few times. Ruined a lot more shafts than I saved though.
I seriously doubt your problem is with the inserts anyway. Which leads us to another issue.
The #1 issue with carbon arrows is they can't come close to matching the consistency of aluminum arrows. You will rarely find an entire half dozen that will all shoot to the same hole when you mount broadheads on them. The longer your arrows, the more acute the problem and, at 30", you're shooting arrows made from almost full length shafts. I do shoot full length shafts, so I'm intimately acquainted with this problem.
If you had a dropaway rest, you could turn the nocks on the ones dropping out of the group and see if maybe you can bring them back in. You can do that to some extent with a whisker bisquit but you won't be able to do that with a plain rest. Clearance problems are worse than what you're dealing with already.
The problem is the shafts, not the broadheads, not the inserts. If you're determined to stick with carbon, the only real solution is to buy some more and try and get another few that shoot with the good ones you've already got. Put field points on the ones that don't group and use them for practice. Put blunts on them and use 'em for bunny thumpers. They'll do fine as long as you don't mount broadheads on them.
If you want to get arrows you can count on all shooting together, the only real solution for us long arrow guys is to go back to aluminum.