Hey Mike,
I think a lot depends on if Ellis gets selected. If he does you need to dump him this week, if not, the chance is there to keep him until next weeks trades.
I don't particularly like Billings. His score wasn't supported by his stats last week. Dunstan will probably play better in the future, Stevens is still finding form and Armitage has to come back as well. You probably need Billings to average around 80 if you take him, and I'm not confident he can, given the above.
As to choosing between Swan and a Rookie, that comes down to your present need. If you need cash, go the Rookie, if the cash isn't so important, and you need points, go Swan.
The choice between Crouch and Robertson is tough, in general if you are not sure, you should go the cheaper option, if it looks like his JS is ok, and it would seem that Robertsons JS is ok.
Langdon might be closer to cooked than Langford, just based on their B/E's.
Hang onto to Rioli.
Maybe, if Ellis isn't picked, Thomas to Swan/Robertson, depending on need, and Langdon to Cutler.
Good luck