i wouldn't alter anything in FFVII, look how many people brought it because of the way it is...if you changed it, then you change the game completely. Although, i must admit, better graphics wouldn't go amiss, but anything else just isn't viable in any way.
All square would be doing is wasting their money...Each and every FF is supposed to be "original" or "unique", and they are...by producing a remake, then it's just not the same, people are simply not going to buy it.