If I was to chose 3 powers, here they'd be
healer , I think everyone agrees on this.
dull pain removes fatigue. we actually nerfed this ablity to same rules as healer, its insanely powerful otherwise.
call item nobody really talked about it, but there is ALWAYS a need for this one.
everything else mentioned is good in 1 way or the other, but these 3 will likely save your life, AND get used almost every game session.