Just want to clarify the differences in BB shell sizes.

68 is for 68mm shell only?
68e is for 68mm with e type front derailluer (can it be used in 73mm shell or 69mm shell?)
73 for 73mm shell or 68mm shell with 2.5mm spacer?
73e for 73mm shell with e type front derailluer or 73mm shell with spacer?

Now for the question. I have a FSA Platinum Pro in 73Ex125 (shell is 73). The threads on the cups seem longer on this BB then the standard 68/73 BB. It is possible to use more then one 2.5mm spacer to get a better chainline on a 1X9 setup? Could this be done with a 63mm shell? I seem to remember that there used to be BB's that where adjustable right to left.

Bill