John,
For 1/8 inch BB I would use a #3 Ultra reverse this will help reduce tearout and the fuzzies. As for your last couple of projects having cuts that were not 90 degrees that could be several things. It could be that when you are cutting you are applying sideways pressures and actually bending the blade out of position. Another reason might be that the saw itself is out of square. That is the blade is not square to the table. This is not hard to check periodically. Practice will help keep those cuts square.
DW