This is where I think Tony's act is flawed. I mean, lets use guns as an example.
If you own a gun you have to have it registered, regardless on intent to use. So when Cage said he was just going to stay in his apartment and not do anything in the recent New Avengers issue (or words to that effect), he was in fact wrong. He can't do that. He's still a potential weapon, and needs to be held accountable.
My main problem is with, say, a mutant with the ability to change Coke into Pepsi like you said. That would be like registering a water gun. It can cause absolutely no damage at all, except gun rot, and that's not the point of the SUPER HERO registration act.
Altho, now i'm going to contradict myself, the name of the act actually puts Cage in the right. And it also makes Tony look like a ****** for backing it. It's a super HERO registration act. So, what, villains don't need to bother? Hey look kids, there is Ted Dawson, he has the power of a million nutron stars, but guess what? He doesn't want to be a superhero, so the law doesn't appply right? Wrong. They've (The pro side) clearly shown that regardless of intent you're going to be arrested if you don't register, so at this point, i'm totally lost as to who the law affects and who it doesnt.
The X-Men are not picking a side. They aren't pro and they aren't anti. They're Switzerland, I think was the world war 2 analogy. Now, they're just sitting in the mansion, not doing anything... how is that different to what Cage was doing when he waited in his apartment? I mean, Cage was clearly anti registration, but as far as S.H.E.I.L.D. knew, he was just going to stay out of trouble until the whole affair was sorted. He wasn't actively doing anything, but they still took him down.
I mean, i've probably missed something, i'm not getting all the tie ins, just the main series, and I haven't read it properly yet (i've flipped through, but i'm waiting for all the parts to be out before I sit down and read through it as a whole), so if i'm wrong, just, yeah, tell me. But as it stands, this entire act seems stupid, because Luke Cage (in my eyes) is both right and wrong at the same time.
This may also be one of the reasons why I hate politics