Judge, I would bite the bullet now and do the intake, exhaust and a reflash tune. You will get far more enjoyment out of your ride. TMIC waterspray also.
Possibly a Turbo and Upgraded intercooler as well if you can afford it.
If you get a tune from a good tuner such as Sean at ASG, chances are very slim that you will have any engine problems anyway.
If a piston lets go, or a big end bearing you will then be on your own with no warranty.
Subi's are pretty reliable these days, regular servicing with good oil and sensible tuning is the key.
