Limbsplitter - how much bleed damage over how long?
Disarm - what % and is there a "level cap" per level? Each time I try to use it it says "resisted".
Fire breath - what's the damage rating?
There are more - but someone will inevitably complain and call them spoilers. Skyrim wiki just compiles the cryptic information provided by the game and displays it all at once.
I really wish Bethesda actually put some time into telling us what a lot of these (any many more) abilities actually do.