Fossil gaps don't imply much except that fossilization is rare and dependent on conditions. And there's are definitely lots of well preserved, smooth transitions. I don't even know what you think "bizarreness of intermediate forms" implies, but it still looks consistent with small steps to me. Notably "bizarre" is a highly subjective judgement that really has no place in this sort of argument.

Granted, sometimes those small steps come faster than others, e.g. adaptive radiations. But there's still only so big a change you can make in a single generation that both doesn't immediately render the organism nonviable and gets through all the checks designed to prevent mutations.

Anyway, last I heard the biggest driver for speciation was just reproductive isolation, so unguided genetic drift can make the two sides incompatible.