Yes! If you select some text in a text field you can make it a link using the Text->Link menu option. For it to be clickable you'll have to set the field to "locked" in the widgets menu, so that it's not editible in interact mode.
Another tip is if you save out your deck using File->Properties and then "Export" it'll save in a "locked" version so readers can't see all the built-in menus and such.
Let me know if that helps!
Yep!
To be precise, clicking a link in a field sends a "link[]" event to the field with the text of the link contents. If you write some custom scripting, you can make clicking links do whatever you want, much like a button. If you don't write any scripts, Decker's default behavior for the "link[]" event is to attempt to open anything which looks like a complete URL (starting with "http://" or "https://") in a new tab, and anything else is interpreted as a card name to "go[]" to. Additional details can be found in the reference manual under Events.
