For a long, long, long time I've wanted to do something similar (though I was leaning toward fantasy/supernatural) and as the commenter above says the biggest problem I think anything like this would face is that it is new. It isn't what people know and are used to. I was actually thinking today on a set up like this where everyone would get a set amount of skills they could use and each skill is given a set amount of damage points and a cool down time (cool down being how many posts between the next use) and how everyone could have health bars etc.
I think it's one of those things where if you can get players who are into that then you'll be grand but if the right people don't see it then it's all your effort gone to waste.
Also as the person said above guides and guides and more guides. Personally I'd love something like this but I know not all the RPers I play with would so it's literally the players you get. I wish you all the luck though and will be keeping an eye out for it myself! :D