Yes, I mentioned before that the best way to remove the old bushings is via an extractor kit. I found out that later, after trying using a screw.
Regarding the 0=0, that should not be necessary unless you alter the stopping screws. The spindles I make are the same as on the bike. If the plate does not rest on the stopping screw, it's most probably because the butterfly plate is not centered perfectly inside the TB.
I'm glad you got yours working fine.