They absolutely should be trying to trade players who have value. I never wanted them to pay ARob $20m/per. He’s a great WR, but I don’t think he is elite. And he likely won’t be here next year anyway, so might as well try to get something for him. They should try to trade either Foles or Dalton also.
Honestly, very few players should be safe. They need to pour as many resources into OL and the offense as a whole as possible.
Again, ARob is a player I had hoped they could extend as long as the price was reasonable. It has appeared for some time that is not the case. A great player, but a Hopkins or Davante Adams he isn’t.