If you do it gradually (by gaining EXP) yes but if you do it instantly by editing the value of the level no and the codes for the stats just visually change your stats not effectively and they'll get reset when you reach a savepoint or they'll even corrupt your savegame if you try to save with the cheat enabled or not.
Because finding the addresses for each room is a pain in the a$$ and not all rooms have a special behaviour that you could replace objects with a boss, for example you would be able to replace it but it would freeze or T-Stance. Also the fact that the addresses for the room that have been found was a matter of much luck, most of the times it will be randomly placed on the memory and there's just nothing you can do about it
You can even give a try to FF even though I'm pretty sure it will have the same effect as 00.
1F by the way will mute any sountrack BUT Cavern of Remembrance" but I think the track is being played only on the mission mode selection screens so it's not a big deal really.
For example:
Unused track: The game lists a file called "119desti.scd" but it never actually calls it under any circumstance, if you force it to load it you can hear the KH1 version of Destiny Islands theme.
Removed track: The game lists a file called "065riku.scd" which is obviously Riku's theme. Since the file is removed from the gamedata the game will load nothing, it's just the traces that remain there. Also another intresting thing is that it lists a file (that can't be loaded again since it's missing) "101ice1_132.scd". I'm pretty sure what it is. There's a used file called "100ice1_128.scd" which is "It's a Small World" from the icecream minigame and the "128" stands for the BPM since the track is on 128BPM. So the removed file would have been somewhat of a hard version of the same track since it would be faster (132BPM) but obviously removed since it would have been reaaally hard to beat and really unfair.
I also came across some unused (still on the gamedata so loadable) and some removed (the filename and the path exists on the bgm file list but when the game loads the file, since it's missing, it doesn't load anything) which is really intresting.
_C0 Mirage Arena Model Color Modifier
_L 0x2114FB80 0xFFxxyyzz
_L 0x2172B8BC 0xFFxxyyzz
xx = Blue
yy = Green
zz = Red
The game engine normaly allows values from 41 to C1 when you make an RGB combination on the settings menu, but using that code you can go from 00 to FF and create some really intresting stuff, like for example, FF000000 will create a mate black model or FFFFFFFF a super bright model or some really tinted models like FF0000FF which is a super red model or some spacey colors like FF012345.
DISABLE THE CHEAT TO SAVE/LOAD, I'm not responsible for anything that happens to your savegame.
I'm trying to find also a BGM modifier with little success so far.