There's really nothing that keeps this car from being driven daily; in fact I know there are quite a few people in the States who drive cars like mine daily.
Nitrous is also a good option but my only personal preference against it is that the bottle runs out. But, taking it easy on the road can be a good thing
A GTI-R being sluggish? Definitely something wrong there; good luck finding your gremlins as I definitely know how that goes.
You can e-mail me at
aaron@nissanperformancemag.com and I'll do my best to answer your questions.