Re: depriming live brass?
Unless there is something specifically faulty with the existing primers, I'd just use them as is and handle them like any other spent primers once the ammo's been fired.
While it's true I've never had a decapped primer fail, I don't trust them, and a loading component I can't trust is maybe not much better than none at all, IMHO. Once they're out of the brass, just what would I be using them for anyway? I mean; I don't do handloading so I can end up with questionable ammo.
In the end, maybe the primers are doing better where they are. Aside from a misfire, I've never really had a problem with ammo that I can trace back to the type of primer involved, unless it was a mismatch (non-magnum in a magnum chambering, pistol primer in a rifle casing, etc.) for the application. As for match vs non-match priming, you may be surprised how little difference it actually makes.
Greg