I think the only thing that would solve almost all the issues is taxing the movement of money in all forms at a small rate. there have been some thoughts on it by people smarter than I but the gist is you tax money every time it moves at a tiny percentage rate. the rate is so small that for the commoners are not affected much but the people that trade money or move money off shore or buy up large commodities would be the ones that pay the most. I'm sure there are some downsides to it but there are many upsides too.
I would say in general that you want to motivate money to move as much as possible - and the problem with excessive wealth is that the money is not moving.
In an ideal world, I would tax money only when it is static.
