There seems to be a limit on Ringsof Protection at +2, and Bracers at +5. Plus 5 for the bracers is okay but can the rings be increased somehow. A bugbear might get thru and hurt my wizard at AC12. He might miss at AC17.
It would be no problem to code other Rings of Protection with enhanced bonusses. All we need to do is copy the existing ones and change the AC modifier.
Give your wizard some Gloves of Dexterity. Also, there are plenty of defensive spells like Shield, Mirror Image, False Life, Blur, Displacement and Stone Skin will keep him alive.
There is one ring of protection +3 in th egame although I can't remember where I found it, I've been trying to help mod the game, I think I've done alright? Made rings forge-able, Staves craft-able, and i'm currently adding more wands, Even with livonya's AI changes I don't think being too vulnerable is an option anymore. that said I can't wait for livonya's mods.