I feel like malaphor should just be a more generalized term for all scenarios since they all involve modifying idioms, whether by combing two or twisting one, whether intentionally or unintentionally since mal- generally means bad or abnormal. Otherwise, a malaphor should probably be considered a sub form of whatever term you find for both.
I'm not finding any prefixes that seem better than trans, though I feel like there's one that is escaping me that means something like "twisted."
Possible options: meta, trans, per, dys, dis, para, caco, terato, skew, aniso, morph, neo
Yeah, I vector traced a photo in Illustrator and then adjusted it.