Think you pretty much critiqued yourself correctly. In a 10 team league, Ryan is middle of the pack at QB but won't hurt you. Megatron, Thomas and Fitz with Tavon Austin in a bench slot is pretty nasty at WR. Olsen isn't going to blow anyone away, but I actually think he'll be alright at TE too. And I think an argument could be made for the Steelers DST as a worthy starter even beyond playing the matchups.
But you're gonna spend all season fixing your RBs. Even if Bush has a good year, hard to see him as a RB1 in a 12 teamer, much less a 10 teamer. Same for Bell. It's possible, but realistically with the two of them and lottery tickets like Bernard and Stacy on the bench, you're just hoping for RB2 production out of your RB slots so that your WRs can get you wins.
Which could happen, but you'll end up trading WR strength for RB help in a heartbeat if someone offers the right deal.