So is 10 psi good to store a beer in a corny at 65ish degrees? Or should I go higher?
Doesn't really matter. Just be sure the lid is sealed, and 10 psi should do that.
I've always thought you needed more than 10 psi to seat the lid well. But I could be wrong.
If I'm storing kegs I hit them at about 30 psi to seat the lid. Of course, if the seal is bad they still leak at whatever pressure you hit them with...