Using a formula to return unchecked checklist items

Does anyone know if this is possible?

Imagine I have a column that contains a text value. That text value is a checklist of 3 items. The first two are checked, and the last one isn’t.

Is it possible to …
create a formula that can return the two checked items?
create a formula that can return the one unchecked item?
create an action/button that can uncheck the second item?

I know we can create a table to replicate this behavior, but this is not preferred.

Thank you!!