Actually you a right about 1st question. I can want guest users or everyone access to forms without log in also.
May be forms can be restricted by default. And there can some options or custom paramaters for remove restriction or enable forms for everyone.
Or can be added a Conditional Logic to metaboxes and fields something like if user logged in - logged out - if user role is something which also works in front-end forms...
These are some general ideas.
And about filters, it they are usefull.