Thank you for playing! Most of the listed issues are indeed poorly explained or fully missing.
Wands damage is wand cards multiplied. 3 wand, 6 swords, 2 swords would do 3 damage, but a 3 wands, 6 wands, 2 swords would be a 3x6 damage.
The symbol next to the enemy should indeed be the attack! That sounds like a bug I'm not aware of!
Exact HP seems like a basic thing that should be there from the start, it was already added to an updated version of the game :)
Cups should prevent damage, but not if they are on energy. You have to play them on yourself (assuming you have energy for it)
UI and tutorial improvements are absolutely needed, it is not easy to understand.
Thank you for all the feedback anyway :)