This is a pretty good list, IMO.
The three that stand out to me on the 'not safe' list are Howe, Watts and Grimes. These are the players we expect more from. Grimes has only just made his way back into the team, and Watts and Howe have been underperforming.
I've been a huge fan of Watts, but am starting to wonder if he needs a fresh start.
The other thing to remember is that Roos sees these players during the week, at training, in meetings, and not just on game day. Its always difficult for us to make a proper assessment of how 'scarred' they are, or what their attitudes are like, simply off game day (although i will admit that this is the most important factor to measure them by). This is what I always remind myself of when people question the selection (or non-selection) of certain players.