There is such an easy solution to the "Dancing Minions/Oops I Sold Bran" bug/feature...

To fix this, and keep your minions in the right place each turn for combat effectiveness (so it's not only a bug stopper) the game just needs to implement a Tick Option above each minion on your board that you can select saying "Do Not Move/Sell" whatever the wording.

This would hopefully carry across multiple shop rounds so it does not have to be reset each time, but the option to do it shouldn't break the game to put in at some point soon (obviously it will, but still).