Right now, WikiTree's new-guest email includes examples of surname, location, and project tags, but there is obviously still confusion. The project tag list is very similar to yours. Most new members don't know what WikiTree projects are, so they may be referring to their own recent projects.
Over the past couple of days, the Greeters group has been brainstorming ways to make the examples clearer.
Many new members aren't aware of how tags work, so we need to find a way to make that clearer, also.