If "lock movable property at run time" refers to not allowing a user to reposition your form(s) then here is one option:
At some point during your application, assign the form's "Location" properties to a "system.drawing.point" variable. Then, in the form_move event code simply assign the form's location back to the "point" variable.
Regarding your issue with a "multi-line label" I am unsure what you are asking.
Best Regards,
Earl Francis