Listen to Tom up there: don't tear the engine down unless 1) you are more than capable of putting it back together the way it was, requiring ring compressor, torque wrench, and other more-common tools, and 2) you have a VERY good reason to suspect there is something horribly wrong.
Otherwise, I'd say: if you can get it bolted on right and get her running - try her out for a while. Get used to her. Then judge from your first few rides how badly you would need any performance upgrades. There's also quite a few of us who can tell you which performance upgrades work the best.
PS: I'm a tad over 200 lb. and if my motorbike performs like she hasn't noticed my weight, well, I'm not going to tell her. She seems pretty content to haul my butt wherever I point the front wheel. But if hills starting giving you problems, just let us know the particulars. We can usually help with recommendations.