Passive heals as damages: I'm not sure I understand what that means.
Your Q idea sounds cool, a switch like old aatrox w, right? You dont really hold it down, but toggle between the 2 effects. Nice. A cool as thatd be, youd never be able to use titanic hydra ever again. (Current 3 hit Q is coded as AoE and you cant AA reset with items, or get on hit effects when Q is up, so having an always on Q takes away active item pathing and will add more bugs to Mord as such)
E: No way, Morde wont be Morde if he had cc. He is the only champ in League with no built in cc. The reason you play Mordekiaser is to sacrifice ALL crowd control and movement speed for ridiculously OP damages. Cc is a no go.
R: his ult already does that, and than some. I suppose we can agree on an unchanged ult than