some other problems almost certain to happen are your end cap on the muffler will fall off, and if you're using an NT carb the nut on the choke lever will loosen up causing your choke to come on and killing the motor.
your plastic throttle will eventually break, your kill switch will short out, your master link will fall off (if your chain doesn't break, first.)
if your exhaust pipe doesn't fall off the stripped studs in the first week, it'll get clogged up from the too-rich break-in mixture. this will happen a week before your magneto fails.
your cheap coaster brake will fail, but usually it lasts longer than the sidewall of your tire that'll wear out from chain rub, as long as it hasn't already gone flat from loose spokes jabbing into the tube.
on or about the third day, you'll forget to turn the petcock off and flood the carb, the engine, and the ground under your bike. but again, this will only happen if your float hasn't cracked yet and the studs on your gas tank aren't leaking.
your front fender will probably fall off, which could be catastrophic, but the bike will probably fall over on it's own first, thanks to a cheap kickstand and an extra 30lbs of motore.
eventually you'll get all the bugs worked out (after your 3rd or 4th build) and if you haven't been pulled over by the cops yet, your bike will run perfectly.
and a piston ring will crack and completely destroy your motor.
have fun!