The game won't support official mods so it will need to be hacked and depending on how it is programmed and maybe even protected the possibilities vary. It is highly unlikely that anyone will be able to hack the game in a way to make the changes work in online matches. On the other hand we might get lucky and the patching system NRS put into MK9 could be available to exploit. Through this system it would be easy to change frame data, animation speed, move links, gravity properties and everything else needed for basic balance changes.
What I want to say is simple.
The modding needs to fit the possibilities. Don't waste too much time on dreaming up elaborate changes. Wait until the game is here and then wait some more for people to figure out what is even possible. But I think that's not the main concern here anyway. The port could simply suck and be so bad that no one would ever bothers with it at all. I would also assume that the PC version will not be identical to the latest console version. It might very well come with new fixes and patch changes not available on the consoles. Maybe they even change the controls of the special moves in order to make it more PC friendly. There are just so many possibilities and investing energy in dreaming up balance changes preemptively might not be the best use of your time. Unless you are aware of this and really want to "dream". Then more power to you and "dream on".
