Hey, you're welcome to do what you want with your scene.bin edit. So I don't mean to suggest you NEED to do any of the following (although I apologize if I word it to sound that way). Just consider the following.
Cutting stealable items to generic restorative items across the board, ON TOP of doubling enemy levels will literally kill the usefullness of the Steal command. The success rate of Steal is dependant upon the Stealing character's level, and the target's level. The greater the discrepancy, the higher/lower the success. By doubling the enemy level 'stat', you are effectively doubling steal's fail rate. On top of doubled statistics, stealing ONE potion, after 20 attempts, and over 1000 HP, and 30 MP later, you have one extremely worthles piece of materia.
Do youself a favor. Don't limit the player's options even further than they already are in such a traditional RPG. As it stands, whether you are attacking with the fight command, or a spell, the depth of Final Fantasy's IN BATTLE strategies largely boils down to "Attack, heal when weak." The better you can manage the balance between these two actions, the farther you will go without "botting" for experience. Chance commands like D.Blow, and Steal are there for situational bonuses. If you are doubling EVERY enemy's evade% without regard, you ruin the usefulness of the D.blow materia. You argue that the result is a more risky command? I say you miss the point of scenario design. D.Blow is just a special piece of equipment you use when you encounter an enemy with extremely low evade. Yes, you will deliberately make an enemy with extremely low evade percent, so you can encourage the player to think. Maybe it has very high phys and magic defense, and even a generous helping of HPs, so if you even gave it an element weakness, you would still hardly even deal average damage. How in the world do you make an interesting fight out of something that ammounts to 500 Fight selects, and 120 Cure selects, and 310 Fire2 selects? Well, you drop the enemy's evade stat to near 0, give a player the Deathblow materia, an elemental materia, and a fire materia, and the problem solves itself, but only if the player thinks, and experiments. D.blow + Elemental+ Fire = 4x damage per turn. The remaining characters could still be casting Fire 2. You could either gain 3 more levels, and then simply spam Fire2 with all three characters, or give the player outlets for creativity.
Thus killing the Steal command is counter-productive. FF7 have very limited options during battles. All strategy comes pre-encounter, but the one trick Steal has over all other commands in the FF series, is it unifies ALL encounters in a larger whole. By stealing, instead of buying a weapon, you 'save' money, which can be used toward purchasing consumables. By stealing consumables, instead of buying them, you save money which can be used toward buying unstealable armors. By allowing 90% of the enemies to have USEFUL drop items, you challenge the player to risk the damage. Steal will not be manditory. You can always buy those ethers at town. You do not need that Mithril Sword, because you can just it 5 feet away at Kalm. Let the player have the option to Steal, instead of buying everything, though. Give that command SOME sort of usefulness. If it is at all possible, even make it an attack command like was done in FFX. You don't have to go so far as to make the steal command completely kill certain enemies all together (although, that was the basis for FFX's random encounter strategy. Utilizing each character's stregths to exploit enemy weaknesses, which 90% of all enemies had SOME weakness), but IF it is possible, provide some extremely high defense enemies with a 'stealable' armor, at near 100% success. Get a piece of equipment, which might suck balls, but also drop the enemy's physical (and/or magic) defense by 100%. There are alternitives to the steal command, other than just getting the occassional bonus weapon. It depends whether or not there are provisions within the code to allow for such modifications.
If there are none, do NOT kill the Steal command. It already sucks enough as it is, since it gets one REALLY good run of usefulness near the end, and then becomes absolutely useless. If the ONLY thing you can steal (save 5 ONLY stealable weapons/armors) are items that can't even restore the damage you sustained while trying to steal it, you completely raped an already hurting command materia. It takes up a materia slot. Give the player SOME sort of reason to waste that space, other than to deliberately criple him/her self. Thos 5 rare items do NOT justify the existance of steal, materia, because players will ALWAYS have steal materia equipped during the fights which harbor those rare items. When an option becomes a non-option (you have no other choice), it isn't a justification. It just is. Provide the player options for stealing buyable items/weapons/armor, around the area in which they can buy them.
You don't have to go overboard. Maybe one weapon the player can pick up from a boss one area prior. Maybe an enemy in between have armor that will soon be buyable. Maybe an enemy not long afterward will have a weapon you could have just purchased. Not everything has to be stealable, but most things should. Same thing goes for Morph. I am not as fond of the materia, but if the player is going to spend about as much time trying to deal the final blow with 1/10-20th the damage, give them something back for their time and effort, instead of a kick in the nuts. "Potion"? I'll tell you what I see whenever I steal or morph an enemy into a potion. "Fuck you". Yeah, it is alright from time to time. Like I said, it is risky, but you CAN'T make it risky just to steal an item AT ALL, and then turn around and kill any reason to have tried to begin with.
Double fail rate...? Sigh. Fine. I personally think it is a pain in the ass, instead of challening, but I would rather spend my time in one fight to "earn" a new weapon, instead of spending just as much, if not more time farming gil from enemies. Bear in mind, each time a player decides to steal, instead of farm for money, they hurt their EXP gain. Someone who progresses through the game, stealing from every enemy, and harvesting rare items for money, or just to upgrade their party's armor, will be suficeintly lower leveled that the folks who spent half an hour accumulating enough money to buy a new sword.
So please, think about the thieves. Not every one enjoys using the Fight command all of the time.
