I would double check to see if you still have the shipping blocks, I noticed when my car still had them the door would be harder to close, when they were removed the door closes easily.
yeah as a former F80 M3 owner myself the Mach 1 won't feel as planted as the M3, but there are worse cars out there. I did not think it was too bad, plus it handles rougher roads better than my M3 comp did.