I don't think they need to sell everyone but i feel like everyone should be available for the right price. I really don't want to see them buying right now even if they do get back into it this month. I think you sell on Happ because he could get you back a decent return, depending on if Estrada gets back on track this month he could bring back a alright return but if teams are willing to give you a good price on Stroman, Sanchez or even Osuna you should be listening.
I am afraid if you stand pat and keep this core a of players we are going to be doing what we did for the majority of AA tenure and that is a .500 team with nothing really on the horizon.