My view on it is like this -
The very first thing I do with a new install of Windows is to go and disable the UAC entirely. UAC is completely a waste of time for users that are in good security practice otherwise, such as running Malwarebytes scan every so often and also have a decent antivirus installed (MSE, Kaspersky, Avira).
UAC is most helpful for perhaps the grandparents that have limited knowledge of pcs, or any other users that might fall into that category. Users reading this are very likely to be above that level, for sure.
I've been using different versions of ZoneAlarm for probably 10 years now without issue, on multiple machines. I currently use ZA Extreme and tweak it so the ForceField service is not started with Windows, which protects browsers. I have other means for protecting Firefox, such as the NoScript, RefContol, AdBlockPlus and BetterPrivacy plug-ins. And I too run Ccleaner all the time, which isn't necessary but I simply enjoy it lol.
The main thing with keeping something like ZA working well is to make sure it auto-updates its versions or you manually do so yourself from time to time.
If you don't run ZA and have any suspicions about network connections, you can open a command prompt and run this command:
netstat -anbo