As others have said, those things are to be expected, but I understand your frustration with giving them time to prep etc.
A couple of things to note though. First of all, the front end is not Nismo, it's much better than the Nismo, looks similar but its a Poly rather than fibreglass and because the lip is better designed than the Nismo afterthought, it looks much better. May have been painted on the cheap, hence the bad condition.
Secondly, the Nismo exhaust system is resonated, I'm pretty sure of that, just a little less so than OEM. So flywheel chatter will be heard. However, we can't hear it, you could, so maybe it was very excessive and a new flywheel etc will be required, which may explain the butt dunno a little.
Like you said, looks great in the ad, but if you're not happy, you're not happy