Moon can work well at 6 with the right partner. with the wrong one he'll look awful for the most part. I actually think he should go back to what he does best and just focus on running. There's no point in him trying to develop game management etc now, and as you say he plays basically the same at 4 or 6. Andrew Johns recommends that any halfback out of form should think like they're a second row, and concentrate on hard defence and running, as doing those basics lets them play themselves back into form, and it seems spot on to me, especially for a player like Moon.
I don't think anyone can tell where we're at until we get some props back, but there seems to be a mindset issue. Its one thing to try to defend a narrow lead 2 minutes out, but we seem to consistently go into our collective shell way too early. That just invites the opposition back into the game, as even defence becomes more conservative - trying not to complete tackles rather than defending aggressively leads to massive yardage by the opposition.
On the plus side, Myler is generally looking the part. He needs to take control at the pointy end of games though - letting an offloading prop try to even partially run things is a recipe for disaster. He does need more support from the other spine players though - Parcell in this team could do more in terms of setting the team up. Walker would make a difference as well.