Cannot kill Bitdefender process after uninstalling it, no launch daemons found
It is blocked by one or more of the extensions it installs: FileProtect.kext, SelfProtect.kext, TMProtection.kext

You should always use Bitdefender's uninstaller at /Applications/Bitdefender/BitdefenderUninstaller and not these other apps you mentioned. Follow the instructions at https://www.bitdefender.com/consumer/support/answer/1784/

If that doesn't work, that page links to another page that covers the manual removal process. https://www.bitdefender.com/consumer/support/answer/1446/