Thanks I'll definitely check the plugs like you said. If its too rich, I might just start by removing the restrictor from the air filter. That's easier than taking the carbs apart
I use the bike for a mix of commuting and fun, so it probably wouldn't hurt to mess with tire pressure. If I have the money, I'll try the sprocket change after I've fixed everything else I can. Thought about fairings for aerodynamics too, but the ones I've seen cost more than half of what I paid for the bike