Is it okay to compress application files? (Especially licensed applications)
Most macOS applications are not actually like 'any other file' - they just look like one - and are actually a folder of files called a package. Right-click on most apps, and you will see a Show Package Contents command. Click that to see the folder structure of the app. 

That being said, applications will compress and expand just fine. I've compressed and expanded Adobe apps with no effect on licensing so long as they are expanded onto the same system.

Compressing an application and expanding it on a different system may break licensing if the licensing mechanism itself resides outside the app's package, or if some other licensing scheme is in effect. There is no generic licensing scheme for all circumstances.