The information given above your hasn't changed in this now very old topic.
Key loggers can be both legit (business/parental installed to monitor activity, etc.) and malicious, depending on who installed it on the system - this would then be considered a PUP as outlined above - enable PUP scanning.
The fact that you highlight the use of the safezone to combat key-loggers, doesn't mean that avast doesn't detect key-loggers. The safezone is only in the Pro/AIS/Premier versions not the free version.