He didn't need a casting couch. He was starring in movies since he was a tiny tot (The Meglin Kiddies). By the time he was a pre-teen, Metro had signed him and groomed him for adolescent roles. By the time he WAS fuckable (and make no mistake, during the 1940's he was VERY fuckable), he was a major star. The Judy/Mickey pictures all made good money. Andy Hardy was a huge moneymaker for the studio. The studio needed HIM, not the other way around. If he used any casting couch, it was of his own choosing.
Well he never sucked my cock.
He was genuinely a major pussyhound.
What ass do you mean, OP? I can't see Rooney's. Can you?
OP, you might doubt a great many things, but unless you can support it with some persuasive reasoning, then few are going to share your conclusions.
I'd bet Mickey Roooney is about the least likely person on the planet to have been couched. Certainly not recently at least.
Didn't he have a well-known affair with Norma Shearer after her Irving died?