Congratulations on a fine purchase!
No, your not nuts at all. Everyone else is nuts for being too chicken shit to take a chance on one!!
If you can stomach the iffy parts situation, a waiting time issue, the bike is one hell of a deal.....bike to bike one of the best values out there. Look at all you get for that pocket change vs. everything else. Add in the lack of service/warranty and things change a little!
But the more you get into the bike and deal with things yourself the less it's of a concern. I've had no problems with mine, and the more I ride it the more I love it. I'm contemplating buying one for a track bike, it handles so well and has the kind of power that's perfect for aggressive track days without worrying about "too much power" and the possibilities of high siding it. A smooth handling bike and, when geared right, an absolute missle
I would change the sprockets to a 16/45 combo, and you can use the original chain. This eliminates the low rpm judders, closes up the ratios and greatly improves the acceleration of the bike. I would'nt even worry about any reduced top end....it's insignificant. That's all you really need to do to it during break-in. Opening up the airbox lid (removing it or drilling some holes in it) along with a freer flowing filter, along with exhaust and a Dynojet are things you could do later with good results. Other than that.....