I'll chime in with some field experience:
There's no extra fees for shipping them. Order more than $200 worth and there's no shipping fee at all.
I haven't had any problems with the Rifle primers. I've been loading them into .223, and so far they've all gone bang out of an AR-15. Same for Large Rifle with .303's in an Enfield.
Small Pistol ones on the other hand are a little problematic. They are a bit hard for pistol primers, and may fail to fire in striker-fired pistols. Hammer-fired pistols shouldn't be a problem. Anecdotally, my M&P9 hates them, I get at least one light-strike every mag. One day I borrowed a Jericho 941 and pumped a full mag full of light-struck rounds through it, and only 1 finally failed to fire.