Well I know that they are changing the fighting engine and all of that ,but I think the characters body types should be included as part of it.(i.e. Ripped chars. should be slow ,but powerful;Average chars. meduim speed and power;Acrobatic chars. should be quick).I think it should depend on the movement of the character.It wouldn't really make sense to me to see a character like Goro doing quick combos and high kicks.
Big characters like Goro,Kintaro,etc. should be slow ,but indeed very powerful.Maybe they could have some unblockable moves.It would also depend on the attack they are doing.It would make sense because if they are doing some kind of hard punch you would have time to dodge it and it would be completely fair.Fighting a character like Liu Kang and Kung Lao would kind of also depend on their movement.They are average speed and power.
You would never have to play online saying that someone is cheap by choosing certain characters.All characters should have their own unique styles of fighting.(Not fighting styles like in the past MK games)
A different kind of parry would also work.A sort of reverse that's quicker than the MK:A one and a bit easier to use than the MK:DA one.Like maybe slap their hand or leg away then lean in for an attack or special move..
I would really like to see this in an MK game.