Austin - Bryant is almost a wash DMC - Charles again could be a wash with charles injury woes and DMC looking like he is finding his stride. As a Charles owner, I hope he'll stay healthy and rack up some serious point but that team SUCKS. You're definitely losing in the QB trade and you gain steve smith...
If you're going to make this trade happen, I'd look for him to replace the WR angle and give you an upgrade. Maybe keep Austin out and look for something like Smith/RGIII/DMC for Steve smith/AJ/Dalton/Charles. That way you're getting a for sure upgrade somewhere for your loss at QB production.
12 team auction (100$) Wilson 3$, Dalton 4$ Foster $30, Charles $16, Tate 2$, Wilson 10$ V. Jackson 10$, Boldin 3$, Garcon 4$, Witten, 4$, T. Austin $5, Patterson 2$, Tate 3$, Dobson 1$ Tucker, K 1$,Tynes, K 1$ NYG D, 1$
leave DMC and Charles out of the trade, we have RGIII/Austin for Dez/Dalton/S.Smith now let's take Austin and Dez out of the equation, we have RGIII for Dalton/S.Smith, now if league is anything smaller than 12, getting Dalton through trade may not be the wisest thing to do, therefore, it's more of RGIII for S.Smith, which sounds pretty weak.
let him keep Dalton and start Flacco, and try trade RGIII for AJ, Rice (if it's passing td 6pts league), or at very least, Fitz
RGIII/DMC/Austin for Dez/Charles/AJ, Rice or Fitz
work on getting Dalton when he realize 3QB is only taking his space instead of helping him, that's when you can trade some bench for Dalton.
See I'm in the minority on RG3, I think you should sell high on him because I think the big hit that takes him out is inevitable and you already got flacco. The only thing I might try to do is see if you can get fitz instead of smith but if he didn't bite I'd prolly take it.