Chances are that only OCD people like me worry much about vibrating things apart when driving, that being because most of the vibration comes from the engine. Staccato impacts of rough sidewalks on a rigid frame aren't the same as steady humming vibrations from an engine, which mainly causes nuts/bolts to loosen up.
Standard maintenance procedures for your kart should include a good visual inspection every time you're about to drive off in it. Missing nuts, things hanging or out of place, bent things, leaks, etc. Going further, a physical shaking , knocking, pulling, even kicking the tires, etc. all over stuff isn't a bad idea when looking for what can't be visually detected, at least often enough to be safe.
OCD me buys nuts/bolts in box quantities, with 2 nuts and a lockwasher for every 1 bolt. Why? Because OCD people don't have as much doubt when every bolt has been double-nutted tightly together wherever it reasonably can be, so that there's no way it could vibrate loose. Don't even have to inspect it regularly, but OCD people will anyway, we can't help it.