The wtParts are only a problem if they exist in a different status than their related part. Windchill otherwise doesn't care if they don't exist.
You need to have the item view to revise an item, not a folder view. Your attached document only shows folder views.
Also, I think you can create a new revision from Creo with File-> Check-in -> Check out and Revise. I'm away from the workstation, but I think that's where it is in Creo 2.