Why does the thought of other people taking your money to spend (or telling you that you should spend your money) on what they see as "good" not offend you?
Do you assume that their version of "good" is the same as yours? You've already made some fairly declarative statements about the kinds of charity that you think are worthwhile and the kinds the you think are not.
The anger comes from having others tell you how you should spend (or give away) your own money.
That's the answer to the anger question.
There is a deeper issue, though. There is a process by which wealth is created. Those who think in terms of redistribution, in my experience, disbelieve in wealth creation. If you believe that money is zero-sum, if you believe that if there is a lot of money over HERE, but not over THERE, then "HERE" must have "stolen" that money from "THERE". After all, there is only so much "stuff", and the true and noble goal is to make sure that everyone has access to the more or less the same amount of stuff, right? That's only fair! That some people have too much, and others too little, is a priori proof of an overall societal problem, in this view.
If instead, you believe that wealth is created; that in spite of a finite amount of resources, the arrangement can gradually be optimized to create wealth out of "nothing", then it is obvious why some people are "super rich" and others are not. Those people that are super rich achieved that status by arranging resources in a more optimal matter. The planet earth had more or less the same stuff as it did 10,000 years ago, but until a few years ago, it wasn't possible to arrange any of that stuff into an iPhone. Until half a century or so ago, it wasn't possible to arrange that stuff into spacecraft. Until a century or so ago, it wasn't possible to arrange that stuff into antibiotics. I could go on.
The process of creating wealth, especially on a large scale, also creates large concentrations of wealth. Everyone benefits from computers and cell phones, therefore the pioneers of these fields accumulated vast amounts of wealth more or less proportionate to those benefits. And those benefits scale upwards very quickly: roughly equal to the square of the number of "nodes" on the networks linking those computers and phones (http://en.wikipedia.org/wiki/Metcalfe%27s_law).
Given that geometric scaling, it is easy to conclude that wealth has become too concentrated, that it must be spread around more. But that conclusion neglects why the wealth exists: the mass benefit to society. Individuals don't have the benefit of extra money in their pocket that might be redistributed from such excessive concentrations, but they DO have the benefit of the computers in their lives, of having access to a cell phone. These are things that could not have even been purchased in 1973.
And we take all of these benefits for granted:
And here's the kicker: if we got together to redistribute all those concentrations of wealth, we would certainly be able to give people more money in the short term, but we wouldn't really give them more wealth. Instead, we would have destroyed the process of wealth creation.
Now I'm not asserting that the "super rich" are morally upright, or that they "deserve" what they have. Rather, I am saying it's part of an overall process of wealth creation (and, to be complete, wealth destruction, but that's another topic), and while it's certainly possible redistribute (via taxation) some of it, excessive policies in that vein will severely restrict future wealth creation.