Stamina does not affect the dmg of Bash (tested)
Wearing anything other than a 1h+Shield reduces the dmg of bash drasticly. Bashing with fists is next to nothing, bashing with other weapons is somewhere in between (probably the base dmg of bash without deadly bash applying) and bashing with a shield gives the intended output with the applying passive from the 1h+Shield tree.
Wearing a shield solely with no 1h equipped, fist and shield, gives the lowest bash dmg (like having no shield equipped at all).
The quality of the shield does not matter. I do the same shield's bash dmg with a lower ql shield as with the best I have.
Swapping the 1h I have equipped changes the dmg of shield's bash. So the dmg of your 1h is important.
The final question - and nothing in this game is obvious so let's get it clarified aswell: Where does the crit-chance of bash come from? One would say "melee crit of course" but is that really so?
If anyone knows more, especially regarding the crit-part, feel free to leave a constructive reply.
Edited by dw0011nrb19_ESO on 23 April 2014 12:20