Kit is not "hard" but definately not something you want to try your first time under a hood. Several members have installed this in their home garage. You don't need extra tubing unless you plan on changing the STS kit yourself.
Issues are kind of broad. For more recent information, check out the thread by Adkins and IPS. The issues are pretty much the same for all of the Turbo kits and depends how much WHP you are looking to make. ~350 WHP at 5-6 psi. is not a problem as several of us have achieved reliable performance at this level. Trying to up it to 400+ is still work in progress due to the limited amount of aftermarket support.
I would also consider reaching out to Tracy SC2150 as he has a viable kit.