I'm not an expert so don't take what I say as 100% as theyre guesses but....smoke behind the turbo is probably only the downpipe not sealing to the turbo properly; or if your really unlucky it could be turbine housing cracked.

As for the revving; try a new throttle cable and grease up all of the moving parts of the throttle...the spring etc...try it by hand and see if its sticking at a position when you flick it.. If not that check for air leaks and your idle screw hasnt come out.

Some things to try good luck.. NMS isnt to far from you either so you could go there if your stuck.

Dan