Just my personal opinion from experience but I find the Force Mastery powers to be pretty useless, other the FON I suppose. Even with the defense bonuses you're still a weakling, I'd rather focus on powers that help me kill as opposed to help me not get killed. Seems to me the primary way for a blaster to stay alive is to kill as fast as possible.
Also how much better is slotting Combat Jumping Versus Slotting Hover with the defensive IOs?