I thought he had authorized the printing of US Notes, not silver certificates. All three, FRN, US Note, and Silver certificate look similar - but a US Note does not create any "interest on the debt," like issuing (borrowing into existence) FRN's does.
The Treasury doesn't borrow FRNs. FRNs don't increase the interest on the debt.
Right you are! The US Notes were backed by silver. I think I got it straight here: http://www.john-f-kennedy.net/thefederalreserve.htm
It was silver certs, there was a 1964 Peace dollar to go with it. the getting whacked over it part appears to be more of a stretch, Griffin addressed it in the latest edition of the Creature from Jekyl Island (which also has some additional commentary on events up to 2008).