If you set or change a user it should fix itself.

Please try in latest update

Fixed in the latest update.

No plans to add themes.

Fixed in the latest update.

Fixed in v5.1.8.

I understand your point, however, it isn't just to support myself but also with all the expenses of servers, hosting and more that keeps Social Dummy running how it is today. Read more here. I do have future plans to improve and combine products together.