He would have created his own explosions just getting there either from the friction of moving all that air out of his way so he didn't collide with the atoms, or from the nuclear forces involved in colliding his atoms with the air's (and still creating a lot of friction in the process).

It would be like that light speed baseball pitch question and answer that ends up killing everyone in the stadium with a nuclear blast.

And Xavier would have done one of those himself in X2 when he freezes time at the mall... Maybe, actually I'm not clear if his ability is a time stop or if he did a mind control on everyone and made them stand still. There's another one like that in Logan, though Logan is able to fight through it, which kinda makes it even less clear exactly what he's doing. Powers!

Yeah, with the Flash, there's the "speedforce" excuse, but quicksilver has never had that kind of effect given as part of his power set.