I see no major issues with this team. You could do a slight upgrade at RB, surely, but Morris as a rookie put up the franchise record yardage for the 'Skins.
A lot of people will talk about Shannahan's history with RB's and be scared of that, but if you look at the history of his teams, you see that the only reason he platooned was either injury or an ineffective RB. Morris is not ineffective, even with a suspect line. Barring injury, he's top 5 this year. He was third last season, so that's not a reach at all.
But, a second RB would be beneficial for the success of this team, IMO. Do NOT give up Megatron.
"We couldn’t do diddley poo offensively, we couldn’t make a first down, we couldn’t run the ball, we didn’t try to run the ball, we couldn’t complete a pass - we sucked." ~ James Ernest Mora