Bench Bush, especially since Daniel Thomas is emerging as a viable back for the Dolphins. For you're flex, I would go with either Branch or Lloyd. Tough call, but I would also go with Branch for Week 3.
10 team H2H league, standard scoring [NFL.com]
QB: A. Rogers
RB: MJD, S. Jax, J. Starks, D. Murray, M. Bush
WR: M. Wallace, B. Marshall, P. Harvin, M. Colston, L. Robinson
TE: O. Daniels, J. Gresham
K: Sebastian Janikowski