I don't know about the FO - but the video and witness accounts of the captain's behavior (leaving aside non-expert opinions) make it clear HE was not stable, as of that moment.
Sorry, but if there IS a problem with the FO, you don't run up and down the aisle babbling about Iraq and Afghanistan and prayer and bombs and try to break into an occupied loo. You quietly contact the cabin crew and/or the deadheading captain for assistance.
I believe this captain was, at that moment, of "diminished capacity." That does not mean he was "at fault" in some way. We've already hashed over the possible acute medical/medication explanations, and his prior career seems exemplary.
I do look forward to hearing his side of things, if he cares to share them.