I finally got around to checking the wiring at the hatch, which someone had previously suggested in another thread that i had started, and found maybe 5 wires that had severed or were about to. Repaired that and the defrogger and wiper work as they should now!

Moving on, I have discovered another wiring issue where the wt/tn wire that goes to the brake lights had melted through, and was improperly repaired by the p.o., and so i will be having to fix that has well, since i now have no brake lights (at all). On the up side, that appears to be the last electrical issue I've got to address in the foreseeable future.