Re: worn paint: this was how it was supposed to work in the original DDF discussion, but I don't think "paint wear has an effect on anything gameplay-wise" ever made it into the live game. I've certainly never seen anyone complain "I used to just breeze by the cops, but now they scan me every time" and the only changed variable is their ship's paint.
Which paintjob you wear certainly does not have an effect on gameplay, in accordance with the "paintjobs have no effect on gameplay" doctrine. So racing stripes or Reaver costumes don't make you more likely to be scanned - even though they logically should.
There's so much we don't know about the variables that go into the cop-scanning mechanism. For example, we don't know if the cops keep a "memory" of you and your ship, so if they catch you carrying contraband once they'll keep a closer eye on you, specifically, in future encounters than they otherwise would. Or, if they do keep a memory, then how long does that memory last? A day? A week? Forever? Do they share that memory with other cops in other systems? Logically, "yes the cops should remember criminals they've caught before", but it'd take a lot of memory/load time if it had to look up your entire criminal history each time it loaded a system.
Likewise, we don't know if the cops "cheat" and become more likely to scan you if you actually have contraband.