A couple of my friends and I did this install on my car a few weeks ago. It took a long time, but nothing went too wrong. I only snapped one bolt. The rest came off with some effort....and an impact gun...yes, impact gun, not an air rachet, and even the impact gun was barely able to break them loose.
My PS line is still in the stock location, and I didn't use heat shielding (the header is wrapped with heat wrap)--no problems yet. As far as the grinding goes, I kind of expected to have to slot the holes on the one flange, so that wasn't too much of a shock.
The one bolt that I had trouble tightening was the far left (if you are looking at the engine from the front)....that took some contortionist work, but I finally got it.
My car is loud....real loud with the ORP, but I've gotten used to it now. And the power increase in amazing for something as (relatively) simple as an exhaust.