* Is there anything that converts such CUEs into compliant CUEs, keeping all information (REM, INDEX 00, ...) as far as possible?
You could edit the cuesheet so that it became compliant, but you would lose your INDEX 00 entries.
Using the cuesheet from the excellent wiki page as an example:
BeforeFILE "D:\MP3\Ripados\Rush\Signals\Rush - Signals - 01 - Subdivisions.wav" WAVE
TRACK 01 AUDIO
INDEX 01 00:00:00
TRACK 02 AUDIO
INDEX 00 05:33:45
FILE "D:\MP3\Ripados\Rush\Signals\Rush - Signals - 02 - The Analog Kid.wav" WAVE
INDEX 01 00:00:00
TRACK 03 AUDIO
INDEX 00 04:47:32
FILE "D:\MP3\Ripados\Rush\Signals\Rush - Signals - 03 - Chemistry.wav" WAVE
INDEX 01 00:00:00
TRACK 04 AUDIO
INDEX 00 04:57:18
FILE "D:\MP3\Ripados\Rush\Signals\Rush - Signals - 04 - Digital Man.wav" WAVE
INDEX 01 00:00:00
TRACK 05 AUDIO
INDEX 00 06:20:53
FILE "D:\MP3\Ripados\Rush\Signals\Rush - Signals - 05 - The Weapon.wav" WAVE
INDEX 01 00:00:00
TRACK 06 AUDIO
INDEX 00 06:23:12
FILE "D:\MP3\Ripados\Rush\Signals\Rush - Signals - 06 - New World Man.wav" WAVE
INDEX 01 00:00:00
TRACK 07 AUDIO
INDEX 00 03:42:08
FILE "D:\MP3\Ripados\Rush\Signals\Rush - Signals - 07 - Losing It.wav" WAVE
INDEX 01 00:00:00
TRACK 08 AUDIO
INDEX 00 04:52:20
FILE "D:\MP3\Ripados\Rush\Signals\Rush - Signals - 08 - Countdown.wav" WAVE
INDEX 01 00:00:00
AfterFILE "D:\MP3\Ripados\Rush\Signals\Rush - Signals - 01 - Subdivisions.wav" WAVE
TRACK 01 AUDIO
INDEX 01 00:00:00
FILE "D:\MP3\Ripados\Rush\Signals\Rush - Signals - 02 - The Analog Kid.wav" WAVE
TRACK 02 AUDIO
INDEX 01 00:00:00
FILE "D:\MP3\Ripados\Rush\Signals\Rush - Signals - 03 - Chemistry.wav" WAVE
TRACK 03 AUDIO
INDEX 01 00:00:00
FILE "D:\MP3\Ripados\Rush\Signals\Rush - Signals - 04 - Digital Man.wav" WAVE
TRACK 04 AUDIO
INDEX 01 00:00:00
FILE "D:\MP3\Ripados\Rush\Signals\Rush - Signals - 05 - The Weapon.wav" WAVE
TRACK 05 AUDIO
INDEX 01 00:00:00
FILE "D:\MP3\Ripados\Rush\Signals\Rush - Signals - 06 - New World Man.wav" WAVE
TRACK 06 AUDIO
INDEX 01 00:00:00
FILE "D:\MP3\Ripados\Rush\Signals\Rush - Signals - 07 - Losing It.wav" WAVE
TRACK 07 AUDIO
INDEX 01 00:00:00
FILE "D:\MP3\Ripados\Rush\Signals\Rush - Signals - 08 - Countdown.wav" WAVE
TRACK 08 AUDIO
INDEX 01 00:00:00