Working through the necessary evil - the app licensing :)
The plan is to have a 14 day trial that doesn't require any explicit licensing. Just install and run. It will pop up a notification half way through the trial period and it will also say something on the last day.
Once the trial period is over and until a production (paid) license is installed, the app will go into an unlicensed mode and it will activate two restrictions (see screenshot). It will remain largely functional, but presumably not convenient enough for regular or unattended use.
You would then hit /purchase page on the website, go through the purchase process and get an activation code in return. The code will then need to be sticked into the activation form on the client (see 2nd screenshot) and it will fetch the license from the server.
If the licensing server is inaccessible for whatever reason, there's a couple of ways to retrieve the license manually (see last screenshot).
For those with Beta licenses, they will be accepted at the checkout as a discount code.
For those looking at large deployments / enterprise setups, there will be an option for automating licensing process. Get in touch for details if you have questions.