Can Mac App Store Apps be "sideloaded"?
You can copy/paste the application from one Mac to another, they will run as they are self-contained (no files required in other locations).

You may not even need to login to the App Store to run them. I had to install Xcode and Final Cut Pro on a very restricted network environment where the App Store is blocked, the apps ran fine.

Licensing is an issue if you use the apps in a non-personal environment (businness, education). Download and install work the same way.