DazzleDavey - I think you have it right with Aiden Riley. He tries really hard and is one of the best tacklers in the team but has fallen into the same problem as McKenzie with his disposals.
I think you are pretty on the money for the most part.
Being such a shallow draft, it will primarily depend on how many players they can get to the footy club during the free agency and trade periods. I think they will have 1-2 live picks and trade out a few to make trades.
Spencer I think they will keep as ruck depth. Trengove is recovering and back running, unless a good trade comes he is safe.
Depending on Salary Cap and the players coming in Terlich and M.Jones will be kept/delisted. Terlich hasn't gotten a game so he will be the first of the two to go.
Unless I'm mistaken Cross hasn't been given a contract extension as of yet...which surprises me because he has played pretty well. But they may let him go to give space for youth. If they do I hope they give him a development coaching role and play him at Casey as they have done for Shannon Byrnes. I also hope they get M.Jamar as a development coach to help out if he retires as I think he has been great for Gawn, Spencer and King.
I feel Howe is gone, especially if they get a good deal for him. If Garland asks for too much they will let him walk.
Almost certain outs I have (in no particular order):
McKenzie,
Bail,
Jamar
Riley.
Possible:
Mitchie (he has shown a bit over the last few weeks so I hope not)
Cross (as per above)
M. Jones (as per above)
Terlich (as per above)
Hunt - might be rookied but I hope they keep him because he has shown a bit when not injured.
Possible to trade:
Howe (if he asks to go, asks for too much or if the right deal comes along)
Fitzy (lost love with lack of professionalism this year)
Toumpas (for the right deal)
Pederson (not a culture fit)
Garlo possible FA (refer above)
Grimes (in and out of the side and would probably be better for him to get a fresh start elsewhere)
Watts (I like him but if the deal is right they could swing a deal)
Dawes (only if they get something equal to his value, not on current form and would need someone to come in to play his role - possibly Frost)