Pete,
I have found out how to do what I wanted. It was as simple as editing the field.tpl file to add the disabled option to the select menus on the post ad page.
See the screenshot I attached, shows admin panel listing fields, I highlighted the field name field simply because what I done was used that to achieve what I wanted.
No need to remove the old admin function as I described, it's probably more trouble then it's worth to do which I stated in the first post was to remove part of the original customization, the placeholder for the select menus. The text boxes are great, no problems there, it's just that adding a placeholder in the admin area for select boxes (drop downs) seemed great, and it is setup to do that, but I didn't know that if you added text into that placeholder text field for drop downs in the admin panel for listing fields, the placeholder text doesn't show. That's ok though, because for the drop downs, I have used the disabled option for select menus (field.tpl). So for example, the activity type field name will just say Activity Type for the name, and when viewed on the post ad page, the Activity Type text will be disabled, so it cannot be selected in the menu (that's how all select menus appear now). Hope that clarifies what I wanted to do.
Brian
Now to explain this better, i wanted