All the gasping and coughing like he can't stand up...then blam he's all the sudden healthy and vigorous.
Do you have the same problem with Yoda?
I wished they'd explained more definitely about Syfo Dius and Tyrannus and how that worked. I know they let you know Dooku is Tyrannus in AotC.
Leaving things open ended from the moive for the EU to take up is fine, I don't think they should do it backwards.
I don't think they went backwards at all. In fact they couldn't because Lucas certailny doesn't consider anything in the EU as fodder, having the blue jedi girl was a miracle. Lucas had no idea that the CW series was going to add the origin of the cough. He just told the creators that he has this cough. Sounds like you're just frustrated that these things didn't get explained. That's why I don't pay attention to the EU.
With all the problems that ROTS from a craftmanship POV, these aren't even issues.