I think the hybrid rules still need to address movement modes. I was also going to add a bit about disguise checks to disguise yourself as one of the base races, and maybe also a blurb clarifying hybrids involving hybrid races of one of the two base races.
Edit: Movement and disguise are done. Also added a thing for reducing redundant ability score penalties. Still need to address multi-hybriding, as although the rules still function well enough, it doesn't work out quite as intended. Currently, a hybrid race (of 2 base races) hybridized with a third race would mean a 1/4, 1/4, 1/2 split, instead of the intended 1/3, 1/3, 1/3. Probably close enough, though.