You don't need to start again. Just run the update installer (Update 27, 3.97 update) and let it take care of things.

No, not reinstall CC3+ itself, but the latest update (Currently update 27). The update fixes things not just with the core CC3+ install, but also updates files from the add-ons which is why it should always be installed after installing an update (or at the end if you install several in a row) even if you have installed it previously.

Also, as the last step after installing everything, always (re-)install the latest update.

Looks like a dungeon style would be most appropriate. Something like the SS2 Bitmap A style perhaps?

The wizard fetches things from the map template. So you should be able to fix this by editing the template file for that style, which should be found in @Templates\Overland Maps\Wizard