try this for trackpad, test this kexts, backup yours an see if you not have duplicate kexts,
Install this kexts for S/L/E with kext wizard/Repair/Permissions/RebuildCaches/ reboot
for USB problems use this boot flag in your boot.plist: USBBusFix=Yes
or search for IOUSBFamily.kext rollback
[attachment=114210:Trackpad Lion ML.zip]
I may try this later but I think they conflict with the VoodooPS2 ones don't they? I came across these same files before you suggested the VoodooPS2 ones and they didn't work. I think I am ont he right path with the VoodooPS2 ones, just need to find the setting to fix the inverted horizontal scrolling.
Should I try the FrescoUSB kext again with that USBFix=Yes?