BoS= Burst of Speed I think
I noticed maybe a bug when I had master 2-hand fighting and only improved flurry. On the surface of Telos, I couldn't hit a damn thing ( no matter what style of attack I used, normal, power, flurry, etc). It was only once I leveled up and got master flurry that things seemed to go back to normal.
Either that or the mercs on Telos are much more difficult than anything else up till then.
But I can tell you that Master 2-hand, master flurry does major damage (especially with lightsabers). So it will go back to normal for you, maybe try investing a feat or two in two-hand fighting.