Well, in the case of the Mon El feat I posted, he bullrushed at a rate of speed sufficient enough for Val to judo toss him several hundreds of thousands of miles away in a manner of seconds. Someone else can do the math on that for an exact velocity (since it wasn't explicitly stated).
I have a pretty good knowledge of Karate Kid due to researching him in order to use him in a tournament a few years back. The claims in regards to him are in fact all legit, if, admittedly, hard to believe (which is why he was a good choice for the tourney; his feats are based on skill rather than actual superpowers). Considering what he's done on panel, and accounting for the fact he's supposed to just be a base human, it's hard to reconcile it, but it's canon and legit.