In summary this is what you guys have come up with
Different meanings of Mickey Mouse by various people:
By Ross Perot as in “fairyland,” it means: “loony,” “cartoony,” “outlandish.”,
By Carl Doebel as in Mickey Mousing around it means “patently false posturing.”
According to Los Angeles investigators as in “Mickey Mouse Mafia.” It means “powerless,” “pallid.”
According to Webster’s New World Dictionary it means: “childish, oversimplified, unrelated to reality,” as in “a Mickey Mouse college course.”
By Dave Smith as in Mickey Mouse bookkeeping, “a caricature of normal practice.”
A reverse usage: to describe bureaucrats insisting on mindless obedience to regulations.
As in Mickey Mouse music: “Designating dance-band music that is corny, unimaginative, bland.”
According to Random House Dictionary: “trite,” “corny” or “petty,” “trivial,”
It is believed all these meanings arose from: Ingersoll Watch Company Mickey Mouse watches: the originals were cheap, tacky, and schlocky.
According to Urban Dictionary: Substandard, poorly executed or organized. Amateurish.
i.e. Who’s in charge of this mickey mouse operation, anyway?
Repaired in an unsuitable fashion.
i.e. Duct taped together or jury rigged.
1st Dude: Can you fix my bike?
2nd Dude: Sure.
2nd Dude: Here, I’m done.
1st Dude: Dude you mickey moused it!
2nd Dude: Your welcome