A lot of this post is opinion disguised as fact.Taking the statement Betting odds aren't great for these purposes They and a concensus of exper opinion defines expectations. And underferforming is doing worse than expectations.
Talking about a so-called underperforming at slams to justify tinkering with her US hardcourt schedule which has given her superb slam results of F SF SF at USO serves no purpose and probably makes her plight worse since New Haven is where she enjoys playing and is probably her best chance of getting a good result nowadays.
: I know some of you hate betting talk, if you don't like it, don't read this post
The problem with this is it's taking bookmaker odds, and one particular bookmaker at that (who are also known for being one of the worst). Bookmakers odds aren't the true market value, they aren't the true expectations. The Asian markets are the true market value, they are the true expectations (to an extent, in tennis it's nearly always true, in stuff like football there are other factors, I will only give explanation if asked though because it's irrelevant to this). Contrary to what bookmakers claim, the amount of odds making they actually do these days is nearly zero, they pretty much only get involved in pricing things up initially. After that they just move their prices in line with what is going on in Asia, and align appropriately to what they want to achieve (explained below).
Sharapova is a popular bet with bookmakers thus they undercut her price massively. You see this with current USO odds. Sharapova is best price 7/1 with the bookmakers, Azarenka is best price 6/1 with the bookmakers. In full market odds Azarenka is trading at around 8/1, Sharapova is trading is trading at 12.5/1. Notice how much more of an edge the bookmakers have taken on Sharapova, because she is a more popular bet, thus people will back her at any price. They want to reduce their liabilities, this is why bookmakers will consistently put up crap odds on Kvitova, Robson etc. On the flip side look at Serena's USO odds. 10/11 best price at bookmakers, incidentally this is around the exact price she is trading in markets. You may ask isn't Serena a popular bet too, why are they taking next to no edge whatsoever opposing her. The answer is because the vast majority of bookmakers target audience don't back 10/11 outright odds over a 2 week period. They want a "bit of value" so look elsewhere.
You can see the very flaw in the USO 2010 prices. Sharapova 7/2, Wozniacki 7/1. They played in R4, prices were Wozniacki 1.73-2.35 Sharapova. It's blindingly obvious from the form guide going in why Wozniacki was a bigger favourite, but you have to remember how bookmakers operate. Bookmakers aren't really in the business contrary to what they tell you of taking serious bets. They will never take someone plonking down like 10k on on of these outrights. They want the thousands of people who will come to a grand slam, and bet like 25 quid on someone "for interest", to these people form guide isn't really of interest, they just want to back Sharapova because they know her, she's hot, whatever.
Anyway enough of that. The reason I say betting odds aren't great for these purposes, because if you are using this, you are getting into the territory of Caro was never the best player in the world, never actually expected to win majors etc. The truth is though if you'd taken Caro's average odds to win grand slams by now, expectation would dictate she should have won at least one, so in that sense she has still underachieved. By the same principle, her averaged odds extrapolated to the future from this point will say she should win none.
A couple of quick points on your individual event points. "Wimbledon : R4 - better than the only other tournament on grass - Eastbourne R1 loss."
The Wimbledon odds don't pay much attention to what goes on in Eastbourne. Radwanska, Kvitova lost early this year, their prices barely moved as a result. Eastbourne is highly unpredictable every year, and too many of the best players are missing for it to be truly used as a guide.
Pinning the exact point where her decline started is debatable. It tends to be thought of somewhere around Roland Garros 2011-Canada 2011 though. The USO 2011 odds you posted are slightly flawed on top of the points posted above. They were taken before she won New Haven, late money will have come in for the world number 1 winning the week before a grand slam. I have her starting 4th favourite, but I also think my odds are taken after the draw was made (Azarenka had a terrible draw here).
On this point: "Finally AO 2012 well into her slide. So with no good results at other tournaments - now you expect her to beat Kim - a player she has never ever beaten and that she's an underperformer just at slams because she doesn't?"
Clijsters was very beatable here. Point is often made how Caro had it hard, she had to always beat one of Clijsters or Serena on her way. What are we hoping for then? That she just gets a dream draw with zero obstacles in her way? Rarely going to happen. Azarenka also had to beat Clijsters to win her first grand slam title here, Caro had the same opportunity here. The betting odds for this were pretty much 50:50, and Caro had her chances to drag it into a 3rd when Kim was looking tired, but she didn't.
On your final point. It still ultimately hasn't brought her the ultimate prize. You try things, you tinker, trying to find that extra couple of %. The schedule completely backfired on her last year, it likely played a major role in her going into the US Open injured. You can't just ignore that last year she went out R1 on top of the good results in the years prior. On top of this Caro isn't in the position anymore where she should be passing up easy ranking points. Look at the draw in Stanford this week, far softer than the draw in New Haven. You of course have to balance these things out, but something needs to be looked at as to why Caro is joint 28th in terms of grand slam points earned in the past year (she was in a similar low position last year), because for a player of her calibre that's simply not good enough.