Do it mate, will totally transform the car... Torque spikes are what ruin the clutch and give traction issues... If possible get a linear map, you will still have all the power and torque but it will laid on smoother.
You don't mention whether you are manual or DSG...
It also a good idea to take a look at the condition of your DV, easy check on K04 in the engine bay, 3 bolts, 5 mins on and off. I'd also look at the cam follower for piece of mind...
The K04 turbo in the Pirelli is good for ~400bhp so you're well away from its max at a stage 1 tune... And the Pirelli engine is stronger than a normal GTI... Stage 1 is well, well within safety limits.
Only thing is, you'll need a brake upgrade when you increase by 70break or so... R32/Golf R etc callys are a favourite.
Get down to rTech for the proper checks and one of the best maps for your car.