Frankly, I'm cool with Earl learning Trial By Fire but with these CB injuries mounting up, you kind of need to protect these other DBs a little bit more now. So I can see the concern there.
I don't think James is all that bad, I just don't think he fits the 49ers system all that well, he could excel with a change of scenery and in Cable's ZBS.
Furthermore, I wonder if the Ravens would be in the market for an RB. For me, Robert Turbin for CB Chykie Brown would be interesting. Brown has 4.4-4.5 speed at 5'11, 195 pounds, 36.5 Vert, and 33 7/8th inch arms... yes almost 34 inch arms. He's basically Walter Thurmond 2.0
James and Michael can compete for playing time behind Lynch. And James could also assume PR duties. I like it. CB depth becomes solid again as Brown can play inside or out, RB depth takes a hit, but at least you put Michael into the fold of actually getting snaps. And the possibility of keeping Lynch around for 2015 is slightly better as well with Turbin off the roster.