Need Lineup Advice, and Should I Make a Trade?

First off, this is my team:

12 team .5 PPR

QB:
Brady

RB:
Murray
Reggie Bush
Frank Gore
Ivory
Devonta Freeman

WR:
Dez Bryant
V Jax
Mike Wallace
Kelvin Benjamin
Hartline

TE:
I had to drop Reed, that mother-fricker, and I went with Dwayne Allen(Colts) for the week.

Now my questions;

1)who should I put as my starting line up? Outside of the obvious ones, mainly at the flex (Gore, Wallace, Benjamin?)

2)will I be fine with this roster, or should I try and make a trade? I feel good about where I stand at WR, but pretty scared of my RB situation. This is a .5 PPR league, so Bush can be a solid contributor, however Bell takes touches away. And for Gore, we are already seeing Hyde take touches.

3)Should I trade for a RB/TE using some sort of combo out of my roster?


So for this weeks lineup:

QB:
Brady

RB:
Murray
?

WR:
Bryant
V jax?

Flex:
?