Well as for the humidity I can't say, but you could prime a few cases with them and try to fire them in your rifle (no powder/bullet, just a case with the primer). If you use them in place of regular primers start back at the recommended start load and work back up, they may or may not cause pressure problems. As for use in other calibers, they will fit in any case that takes a large rifle primer. I don't know off hand if the .22-250 or .243 do, any good loading book could tell you.

Good luck.