These are good tips! We also found out that toggle buttons are very useful for a continuous action like attacking. People have hard time pressing buttons fast or pressing buttons for long time. This also means that there needs to be a reason not to hold button forever. You can get creative here and punish player for holding button for too long.
Another thing we learned is that major tremors happen when the players get sensory overload, get suddenly excited, surprised or scared. Essentially losing control for brief moments. This means not to make a very intense game. Try to avoid visual or audio unexpected things during gameplay or do that in non threatening game scenario.