A 215: Looking at that, they key part is in the disguise self spell. 'You cannot change your body type.' Is the key part of rules text. Now... it looks like they're saying you have to remain whatever type you started as, i.e. Humanoid, Abberation, Animal. They could have meant 'if you start as a human body you have to stay a human body', but RAW, they clearly said 'type', which is a rules term which has a meaning.
So RAW, you can change into anything which is the same 'type' as you within the height and body-only limitations of the Disguise Self spell.
What that means in terms of gaining Ex traits I have no idea.
Also could easily be overruled by rules text somewhere else (that Racial Emulation feat for example).