Hehehe, what did you expect? Options are like your own back side, everyone has one.
Superb job as usual.
Well i used trainer only for gold cheat on normal difficulty (no friend fire) and this sound keeps happening so thats not the case :P
it's still working, the XP is actually cumulative. so if you jump levels, you need alot more XP to actually 'reach' the XP that would be normally there for that level.
if you are level 2 and it shows you have 200 XP, you actually have 1200 XP or something ( 1000 XP for level 1 then 200 XP for level 2). so if you are level 10 and were originally level 2 then you will have to earn alot of XP (or use the XP option to add XP) before it becomes enough to be visible as XP for that level.
the game is not broken, you just added a level to the XP that would normally not HAVE that level.
party health may lower somewhat during combat but it should NOT go to zero.
likely it will reset to the amount of health of the person you were using when you activated it.
for instance if the main character had 600 HP, then when you turn on the option and enter combat, all characters will be locked at 600 HP, even if they had 10000 HP. this is so insanely high HP of the original trainer doesn't mess with the way the game calculates damage in certain situations.
unless you have a character that is health 10 running with characters who have health of 10000 and you turn the option on while controlling the character with 10 health, it should not be a problem.
you can turn options 1 and 3 off and on again every so often to reset the health it writes to the current character you are using.
regarding the combat music, if this is the case the obviously the trainer is playing a mp3 file for it's sounds and the game must have insanely amount of mp3 or sound files playing at once and the two clash in the number of sound channels that can play. not sure at the moment what to do about this, as this seems game specific and not really a 'trainer' bug as the trainer sound generation has not changed in a year or more.
not sure y that happend to you when i started my first game i used hp and group hp and all and didnt have that issue dont know why that happend to you but i hope it works