The Facebook is original inside LeeDroid. I never download it from the market. No idea whether its Facebook For Android or Facebook For Sense. Cause both of them seem same to me

Try clear the cache. I cleared it and it's working again

Manage application ?

and do post it up at screenshot threads, easier to share what apps n icons used if u posted there as many others r looking at that thread 
erm.. not quite sure.. r u on eclair or froyo? i had it running bad once when i played on 2.1.. now on froyo its quite smooth.. even slightly nicer when overclocked at 1113mhz.. im playing fifa 10 AND digimon world now using psxandroid 
im recommending a reset or a reflash i guess.. seems like others are having fb android working well on that rom except you. Try a reset 1st. If that dosent solve, reflash the rom. U dont have to make backups since you already made a backup this morning ait? I would recommend keeping a track of your backups organized btw. I personally made folders. Mine = (HTC Desire/260710 "ROM name here which you came from"/SDbackup) .. Thats how i organize my backups on my pc so it would be easier to track and copy back which backup i want. I also made a special APK folder containing wut apk installers i have so that i would not have to re-search and download them. Thats how easy i flash rom and copy back. but what im losing is time which is not replaceable.. haha

there is no force to go to the darkside, android is not that evil btw. Surely it will worth the wait  .. but u better tie down ur hands then otherwise it will get pretty itchy soon 
Patience is ur friend when flashing. Worth every minute