BS is an autocrit from the rear if you're in opo-opo stance, yes.

As for a solid PB opener:

Quote Originally Posted by NoctisUmbra View Post
Demo > BfB > Snap > IR > Snap > Steel > DK > Howl > Snap > DK > Twin > ToD > Demo > Boot* > True > Snap > DK > Twin > Snap > etc...

*Alternatively, one can replace this Boot with a DK, and make it so DK never drops. Should the DK here crit, it would be no different from a Bootshine anyway. On the other hand, if it does not crit, the DPS loss from it is theoretically greater than the DPS loss from having blunt resist down for 2 skills.