Choosing what to do would be a great idea!
It makes the combat more tactful, and you could attach different statistics (the straight up damage and defense combat is really boring) to different actions. Maybe after a boss, instead of having another shop, you could add a way to upgrade your actions, and in normal shops, you would only have options to heal health and stamina. This also helps with the scaling problem as you only get stronger at 1/3 the rate. I don't know what you will do for the gems after a run, as currently they just make you start out stronger, but I'm looking forward to it!