I run bags and I only ride in about a 2 mile radius, sometimes 5 mile radius. They work great for putting soda cans in when I go to the soda machine. I'll get sodas and just drop them off at my friend's houses for them.
BoFeng carbs are pretty good for a mostly stock, or even performance engine. And most 80cc engines are actually 66cc. You'll want a good front brake at minimum, and delete the coaster brake. I find that rim brakes work just fine if you aren't constantly riding as fast as possible between stops.