These are actually good suggestions. I was skim-reading some of the other comments on the armour issue, and was convinced there was a real problem with the current two-bar system when people reported specialising in pure physical parties or pure magic parties just to get around it.
Your suggestion number 2 is nice, since it keeps some creativity intact. I posted on a separate armour thread about the need for collateral damage when attacking armour, since it’s too one-note and robotic at the moment. It needs to be messier. I’d suggested that attacking armour always damages a % of health as collateral damage. I believe someone else requested something similar.
An attack on physical armour that damages a portion of magic armour would also work for me, in messing things up in an interesting way. It makes little sense, but realism really isn’t important, in my view, in designing an entertaining combat system.
It could also be merged into 1 bar as you suggested, and there could still be magical and physical ‘armour’ – but instead of granting you magical or physical hit points, it could grant you a % resistance to magical or physical attacks that’s factored into the attack on your 1 armour bar, depending on the attack involved.
I definitely think the armour system is highly innovative, if flawed, and wouldn’t want to see a fresh idea burned down completely, as some seem to favour.
Personally, I’m now leaning towards one armour bar, with the ability to build up physical and magical resistances that negate the damage to the one armour bar accordingly (ideally the magical resistances would also be categorical: pyro, hydro, necro, etc).