If my fun is RPing and you walk into scenes where I am and instead of RPing just slaughter all the things, then you're a dick
Does this work both ways? If you arrive at a scene where slaughtering all the things is about to commence, and figure out a way to resolve it all just through RPing where nothing has to die, are you a dick for pushing your preference and ruining someone else's fun?
Towards the main topic, I'd generally prefer that peoples sheets are maximized to describe the character they want to play, wherever on the scale of ability that falls. I can handle folks who want to be the best at everything, or the best at what they do, etc. What infuriates me are folks who can't be bothered to play with the system enough to be as good at the things their character does as they think they should be, and then complain, because they don't feel like they should 'have to min-max', when in truth they just don't feel like they should have to learn the system at all, just put dots where they fit their imagination and POOF it should all work out.
"Medicine 3 implies a 'Professional level of skill' but my character isn't a preofessional, so I'll only take 1 or 2, but WAH why am I reliably rolling for shit on Medicine rolls, it's so unfair!"
Shoot yourself in the foot if you want, but shut the fuck up about it for fucks sake. Yes, it's annoying that White Wolf (and other games) like to tie mundane skills to supernatural powers, such that your magical healing power that has no bearing on actual medicine at all is keyed off of your technical knowledge of actual medicine. Suck it up and buy the dots you need, or shut the fuck up.
Truthfully, I think my real contribution to this is - "twink all you want, but don't let the depths of your +sheet stop my ability to RP or you'll find we RP in very small doses." Even if your sheet is awesome, if you walk into a murder mystery, roll dice once to reverse time to see what happened, say who did it, and walk out - well, good job asshole.
...wait, isn't looking back in time like a level 2 power? How does that even require twinking? And this example is a huge peeve of mine. Murder mysteries are not generally a good idea when involving people with supernatural powers, because so, so, so many of them will sidestep the point of a murder mystery. Shit, peeking back in time isn't even restricted to Mages. Hell, there more than one M+ type that can do it. A relic can do it. If you want to run a murder mystery, only invite strictly mortal PCs.