No one will be coming after you with pitchforks and torches if you customize it to suite your needs. So, no, it's not collectible in that sense. Personally, I'd suggest you ride it as is, with the stem swap, for a while. If you find your hands and upper body numb, you might be well served to swap in a carbon fork. There's a reason most aluminum frame bikes are not sold with aluminum forks anymore. On the other hand, you may find it works just fine for you. The unknown variable about swapping forks is that it can change the handling characteristics if you end up with a different rake and trail than the original design.