All's well with favorites and keybinding but is there a way to set up going from a shield and one-hander to two one-handers (if the one-handers are different --- I know it can be done if they are identical)?

Should just be able to make two seperate keybindings for that, just assign dual wielding to 1 and a one hander and shield to 2.

If you use the same weapon in both hands for DW, and one of those with your shield, just bind the weapon and the shield. Then all you have to do is hit the weapon keybind up to twice to DW, or hit it once then hit the shield one once to one-hand and shield. To switch directly from one to another, hit the weapon bind to DW and the shield bind to equip the shield.