Make Shifty and Goblin Tactics Encounter Powers and they are probably going to be pretty balanced compared to the PHB PCs. Maybe make them useable 2x per encounter.
Make the Drow's Lolth Touched power usable once per day and it will still be ok, but not as strong as it currently is. Plus they will still have Darkvision which is useful.
For the Shifters put "Sustain: Minor" on their powers and the issue is gone if you feel they are to strong.
Remember the
MM stuff is really there for making NPC monsters, those powers are pretty much the standard monster powers written up like PC powers, as such they are really balanced to be used in only one encounter ever, and so some of them are significantly better than the PHB's multi-encounter powers.