Hello Marcin,

Thank you for reaching out to us.

1. We don't offer free trials, but we have a 15-day money-back guarantee.

If you purchase the plugin and find it doesn't suit your needs, you can submit a refund request within 15 days from the date of purchase, and be fully refunded.

Before purchasing, you can also check out our demo and sandbox sites to test the full version of the plugin.

Amelia demo sites: https://wpamelia.com/demos/

2. You will just need to deactivate the license on the first domain. Once you deactivate the license in Amelia/Settings/Activation on one site, you'll need to visit the same settings on the new site, to activate the license there, then do the migration, and then activate the license on a new domain.

You can also log in to our store (https://store.tms-plugins.com/login) and deactivate the domain from the "Manage domains" button. Then, when you install Amelia on another site, just activate the purchase code there, and that's it. 
If you have any further questions please don't hesitate to ask.