A lifetime license includes all new versions of RunJS for life. A perpetual license includes all new versions of RunJS for one year. After one year you can continue using the version you have, but you will need to renew your license to get access to newer versions.
You can renew you license via the license manager.
Yes. To do this, open the 'Manage License' modal from the app menu and click 'Deactivate License'. This will free up your license for use on another computer.
Alternatively, you can also use the online license manager to deactivate your license on a particular computer.
A full list of shortcuts can be found in the docs.
By default, RunJS will display the output of your code on the same line as the corresponding source. For example, here are two statements on lines two and four, respectively and their output results are displayed on the same lines:

In some scenarios, this behaviour might not be what you want for example, if you're running asynchronous code and expecting the output results to appear in a particular order. In that case, you can turn this behaviour off by going to the preferences and unticking the Match Lines option.
