I know there is an FAQ section (which I have read) but here are some specific questions:
-Will chipping my 2.8 quattro 30v be harmful on the engine?
-Anyone here has done it with good results?
-Anything I might want to change before going through with it?

Or any other advice you guys might want to give me, I'm all ears..

 

not really harmful just more stress on the engine,
did it to my 1.8 had GREAT results,
make sure car is running 100% and vag com fault codes that may require repair do it FIRST!!

 

Considering you're looking at a peak gain of 4-6hp and a midrange torque gain of probably 12-15ft-lbs, you'll hardly stress the engine. SpeedtuningUSA (get in on the group buy) is the way to go, simply because it works like the others but costs a hell of a lot less. Don't worry about accelerating your maintenance schedule - you're not going to break anything from the gains.