Physics and Superheroes

Just finished reading "The Physics of Superheroes" by James Kakalios. First off, let me say, great book! Funny and well-written and I feel smarter just for having read it.
Having said that, I do have to confess that physics was never my strongest subject, whereas superheroes are more my forte.
My original intention for reading the book was to base my superhero stories in a more believable realm and ensure their powers didn't violate natural laws.
As it turns out, this is pretty hard to do. Some superheroes are more plausible than others, but almost all require some suspension of disbelief.
So, rather than suffer analysis paralysis, I have simply decided to try and limit the number of "miracle exceptions" my superheroes need in order to operate and try to make them as plausible as can be with the understanding that we must play a little with the laws of physics to make our heroes exist.

It's probably a good thing superheroes don't walk the streets anyway...with super heroes come super villains and I don't want to be the victim of a death ray or anything like that. I have enough to worry about as it is!