As for weekend shipments, that's standard or should be for most breeders/sellers.
I too try not to ship after Wednesday for that same reason. Package gets lost Monday, Tuesday or Wednesday and you have that extra day to work it out and have it delivered before the weekend. If you ship Thursday and it gets lost or shipped elsewhere, that snake could spend 3-4 days in that box before it is recovered and delivered!
It's not worth the risk on either end of the transaction and especially for the snake!