Somehow I've managed to boot the system - it boots and shuts down extremely slow now.
I've put kexts back to /S/L/E (except for VoodooPS2Controller, I left it in /L/E).
From the first look I noticed that battery status is no longer available and it's not possible to leave it in the status bar in Settings (it just immediately disappears)
So far after a few restarts everything's back on track, except - touchpad still freezes and some battery/power management issues are still at place like incorrect battery status when it shows 100% for an hour and laptop just shuts down from battery drain, "put hard disks to sleep" unchecked box resets to checked state and "dim display when power AC unplugged" checked option doesn't correspond appropriately to the unplugged AC. I should mention that with previous version of OS (and kexts) I had no trouble.
That's strange, because overall High Sierra seems to be a much better optimised system...
UPD: wow, my laptop is slowly dying - none of USB ports work anymore (in OS booted)...
I've rewatched everything again, included USBInjectAll kext + customised SSDT - no luck.
Reattaching the reporting files.