Has anyone here ever successfully used SS2.0 to put a clickable URL inside of a sublist? The code snippet here creates a value, but is displayed as text, instead of as a hyperlink. Am I missing something simple?

I haven't done it with SS 2, but you might try calling SS1 with window.[stick method here].

Instead of FieldType URL, have you tried just Field Type TEXT. I know in Suitelets, if you put a URL as a value for that field, NS makes it clickable. Not sure in forms since I have not used it.