A few things.
At higher gear levels, using Project to proc TD provides a DPS boost over not using it, simply because of how much power an optimized Campaign+ Balance Shadow has.
Sever Force typically hits harder than Force Breach for me, largely because it deals internal damage rather than kinetic, which is mitigated by armor.
I believe optimal Saber Strike usage is when you fall below 40 Force, as using it too much higher results in too much of a DPS loss.