I have almost none to zero experience with Galaxo 18.104.22.168, cause I jumped to GAOSP as soon it was stable (nightly releases). Yes it could be no sleep bug. Did you try reflashing Galaxo again with full wipe???
Regarding the things you mentioned under:
1. did you try clear cache under options or reflash gapps again
2. yes, it's known as developers abandoned developing for Android 1.x and gone to Android 2.x stage (maybe you should go GAOSP BETA 2 if you want more apps available)
3.reflash the ROM or battery calibration (a myth), btw it seems that when you unplug the charger (battery full charged) and plug it back in it reads 99%
And use 2G networks only for more battery
main guy on duty for Galaxy i7500