Yes! Once purchased, you can use them in both commercial and non-commercial projects without ongoing royalties. Check out the License page for full details.
Simply download the .js files from your Itch.io library, place them in your project's "js/plugins" folder, and enable them via the Plugin Manager in RPG Maker MZ.
Yes. You can contact me directly via the Hendrix Plugins Discord. I'm active almost 24/7. You can also join the Discord channel to discuss and share with other members.