Nope, the tyres will be fine. Just try and get them to wear down all together by swapping them around and buy a complete new set then. Helps the balance of the car more than anything.
PPP really isn't going to annoy anyone's neighbours, there are louder diesels
Plus there's no point in the PPP these days, just get a decent exhaust system (second hand) and remap, more power, better under the curve torque, just better and cheaper
Sound system wise, take the rear speakers out, they're pants! Put some decent 6.5" component speakers upfront, plus a decent amount of sound proofing on the door cards to stop rattling, and of course on the door skin, decent double din touch screen headunit, maybe an amp, and sorted. Or even add a small under seat sub, or one better a decent 10" sub in the boot.