Did I imagine it, or was there an Inhumans comic a few years back which had a scene that implied that Maximus - while ostensibly a prisoner - used his mind control powers to force Medusa to - how to say it? - perform "orally" for him. And I don't mean "sing".
The Skrulls were faking a LOT of powers during Secret Invasion, and I doubt any of them were being beamed anything from anywhere. At one point they even had a whole planet of X-people who, I think, didn't even know they were Skrulls.
Does anyone remember how the Secret Invasion super-powers worked?
But agreed that shapeshifting is often used by lazy writers without thinking it through. It used to bug me when Odo would change into a mouse on DS9 -- where did all the extra mass go? If it was simply compressed, you'd have a 200-pound mouse running through vents that wouldn't support that weight.
Clayface changed into Superman, complete with powers, at least once in the Silver Age.
Meanwhile, I just read the latest two issues of Royals (I'm getting all the books with the "Marvel Legacy" trade dress through December), and Maximus is part of Medusa's team. So I guess she holds no hard feelings about, you know, rape.