hey... i'm sorry i haven't read the whole thread yet so i'm not sure if this has already been said..
why not use source or cryengine 1.x or 2.0? all three has sdk's and cryengine 2 has a sandbox editor.. it can handle insane quality graphics and scale all the way down to ff7 original graphics..
it has a flow-chart system that you could prolly make the combat system in fairly easily and.. and and (brains overload from excitement) an...aaaaa...
*dies*