You should consider maxing out blasting strike, it's a multi use ability, blowing players away, smacking them agaisnt a wall, flipping tanks upside down, keeping grenades and kegs away from you, prevent jeeps from roadkilling you... in my opinion, it's one of the best abilities in the game.
My soldier is currently lvl 20, so my build is lvl 5 CM, lvl 5 BS and lvl 1 6th sense, now I'm planning on maxing burning bullets (not that I really need BB, but it is better than GS, and 1 point in 6th sense is more than enough.