New version available.
You can now add vendors! It will attempt to make the 'best choice' of vendor type when adding a vendor, if it is not correct, just select the correct vendor type from the dropdown on the window that appears. (And let me know what vendor was wrong)
You can add mailboxes! Click the Add Vendors button with a mailbox selected in the visual editor, and it will add it to the current subprofiles mailbox list.
Mailboxes are now shown in the list of stuff. - Vendors are coming next!
I added the Z coordinate fixing code back in. Keep in mind; if a hotspot is in a tunnel, cave, or otherwise not on the 'top' of the terrain, it will most likely use a bad Z coordinate.