Problem Solved, actually...I had to take the bleeding carbs out again, but the problem was a sticky butterfly shaft.
The two long arms in the middle of the carbs that pull down on the butterfly armature kept sliding out from their little pins...I noticed there was a little hole drilled through the pins they fit on, where the PO must have pulled out the tiny cotter pins when he took the carb apart the last time and didn't replace them, and I didn't notice it when I rebuilt them...I fashioned a stay-pin out of some wire and slid it through each hole, bent them up and over - problem solved.
What the little post was doing was somehow catching on the arms themselves. This kind of locked the butterflys in the Open position, which explains why they only wanted to roll open a quarter of the way, and why I almost got my face blasted off through the carb when I put starter fluid in it: The fluid ignited in the piston, the butterflies were in the Open position, and the exhaust cycle blew it out the throat of the carb. Not Recommended.
So now I get the Joy of putting them back in...it's true, It Is A Btch! Especially those effin upper manifolds...its gotta be done, but I am not looking forward to it. Well, I *am, but I'm not...Biiiig PITA!
But thanks for the help!