A lot of the things you plan to do, have already been done in my edit, especially one that address Vader (my edit is called "A Stronger Vader" edit: http://originaltrilogy.com/forum/topic.cfm/ANH-R-Stronger-Vader-edit/topic/13462/).
I however did not change anything to make it tie-in better with the PT.
Should be finished very soon, a week or two at max.