I would like to see one more option: Disable hashtags.
When selected, "#anything" would be treated as plain text. Also when selected, as with other options like Directory, the #Hashtags tab would not be displayed.
I "own" 2 groups. One of them uses hashtags extensively. The other one not at all. For the "Not at all" group the tab just creates confusion and questions. If the user understands what hashtags do, they try to use them. If they don't it becomes a question of "That is a hashtag?" In either case, it creates questions which require time to deal with.