I know you can achieve parts or all of what I'm suggesting here in some way through existing tools (dummy fields in SQL, custom code snippets etc.) and maybe I'm just too used to other RAD tools. I'm just thinking out loud, topic can be deleted if I'm on a completely lost track here;-)
It would be great to have some pre-defined unbound field widgets that you can throw on a page in page designer, basically like "insert code snippet" but "insert unbound field" instead.
Maybe a date field, a text field and a dropdown. With some properties: validation rules, appearance etc., and hooks for field events.
And of course the scaffolding behind to refer to them in events.
E.g. probably useful for use on pages with an underlying query that returns >1 row (list pages), but you only want 1 general unbound field to ask for a value and do stuff.