Your structure looks nicely balanced, and I like a lot of your picks. For me the interesting ones are:
Haynes. Finished the season with three tons, but also scored 85, 70, 60 and 58 post bye, so I don't see a clear sign that his role has changed favourably, unless it happened very late. Priced at his highest ever starting price, and seems to miss a lot of games. Personally I'd much rather back someone like D Smith - you could swing Hill back, although having he and Dawson on opposite lines could be handy - who has a better record at a lower price and is DPP.
Sloane. I looked at him and he's usually a fairly durable player who is just below elite scoring level. I've passed in him for now as he's getting a bit older, is usually not a very top scorer, doesn't seem unusually cheap and can be quite up and down in his scoring, which means he could be an upgrade option through the year if he gets really cheap. Personally I don't really like to start likely M7 or M8 types unless they're super cheap, and he looks like one to me, but if you think he bounces back or does better under a new coach, he could be viable. Otherwise switching him for Oliver is probably what I'd do.
Merrett. He's a reasonable option in my view but just behind a handful of others. Pretty durable and still young, with top level scoring in his history. For me the question is partly whether Shiel has limited his ceiling somewhat, and I don't have a strong view on that, but might sit on the sidelines until we find out.
Walters. He will be a POD, and my immediate reaction was that he's an unnecessary injury risk priced at his career best, but he's actually averaged 20 games for the last five seasons so that may be quite unfair as it turns out. If he plays substantial midfield time he could be a nice POD for you.