you are 100% right about the repeated instructions and that was a thing that we totally didn't take care of in the development of the game and we are sorry for that.
Combat and movement are made at the start of the game and we were aware of the issues but we didn't have much time to get everything perfect.
the key had 2 uses:
1- make sure the player play a part in the room (for example we put the key back the guard so the player should fight him)
2- we wanted to make levels that have 2 rooms, not just 1 room, but we realized we on last day on the jam.
In conclusion, all your issues god welling will be fixed soon as an update for the game. Thank you so much for your detailed feedback <3