This is completely my opinion, but the carburetor kit is useless with a stock engine. You're better off getting a #90 jet, header, and air filter, and 18lb springs.
Both flywheels are pretty much the same. One is stock, with the fins uncut, while the other one is lighter due to the lightened and cut fins. Overall, they're pretty much the same. Email NR and ask how many RPMs he recommends for this flywheel though.
Depends. AGK/NR sells 2 different types. On rod, the cheaper one, does not include bearings, thus, when the ROD wears, down, you have to replace the whole thing. However, the more expensive one, WITH the bearings, you can wear it down, and replace the bearings only (around $20), and if you accidentally run it low on oil, you don't have to replace the whole rod, just the bearings.
Overall, the bearinged rod is a much better buy. The stock rod does not have bearings.