is the intent to proceed required on loans secured by vacant land and also are they required to sign vacant land or can we just document the file

Intent to proceed is required for any loan subject to TRID, so if the vacant land loan isn't otherwise exempt (open end credit, business or ag. purpose, etc.), yes you must have intent to proceed. Whether you have a signed form for that or document it otherwise is up to you. There's no requirement to have a form, or to have that form signed.

We don't sell loans (anymore), so my mind never goes there. If you do, your investor may have more stringent requirements than the regulation does.