MIchael's looked pretty good when he's played, he just never plays. My guess is he sucks as a receiver and/or pass protector. I'm not sure if Turbin's any good in pass protection but he's very good as a receiver.They do have to figure out the post Lynch years. I think Turban is better than many think. I'm not very high an Michael and think that was a bad pick.
I would be uneasy about spending an early pick on a RB, but a RB should probably be chosen in this year's draft.
As important as Lynch is, if you get better WR's, Russell Wilson should be able to handle throwing the ball more. I think that is how you replace Lynch's production because it is hard to find a RB as good.