a lot of work.. you have to un bolt the current exhaust... bolt on a good exhaust, tune, BAM 30 awhp...

fmic with a stock wrx turbo will be laggy and not much more cooling than either stock tmic or upgraded tmic....

boost controllers are bad if you dont tune, subies dont like to just have the boost upped without a real tune.

if you stay modest with your parts you wont have to worry about your tranny (assuming good driving) but once you get 275-300 awhp/tq then anything could happen (tends to be the older the wrx the weaker the tranny and you picked the oldest possible)