Is it the mopeder?
Is there a moped spirit that makes mischief?
Do mopeders need a patron saint?<<
Actually, it's more along the lines of Ego.
Some folks in this world only feel good about themselves by crushing other people down, and the smaller, lighter moped is an obvious target, not to mention one that cannot easily flee.
Because they are unable, and in many cases, unwilling, to flee - there's a greater possibility of conflict, yes.
As to vandalism or theivery, that's based on younger folks who jealously covet anyone ELSE having something "neat" that they do not have, and if they cannot easily take it from them, will attempt to damage it so that nobody has it.
As fer mischief, I think the discipline of keeping a moped fully operational and in good tune teaches a respect of said equipment, and definately being on the road likewise teaches respect of the road and defensive driving - so as a whole they're more disciplined, coolheaded, and safer, even when operating a car.
As fer a patron saint, I wouldn't know, but I'd nominate Fred if ya backed me into a corner on it, heh.