Hi Michael,
I’m really sorry to hear that this has proved such a frustrating experience for you 
You should be able to create and edit Themes if you are assigned the “Skuid Admin” Permission Set. However, you will also need to have the “Customize Application” system permission, because Themes are primarily stored as Static Resources, and you need to have the Customize Application permission in order to update Static Resources. Basically, if you have the “Skuid Admin” Permission Set and the ability to edit Static Resources, you should be good to go.
