Money has different values depending on the circumstances though, it has a lot higher value when you're struggling to make ends meet than when you've plenty to spare and that seems to be on a linear scale, when you've billions then throwing a few million at a market to push it around is trivial. Risk likely comes into it there and could be considered a currency in its own right.
You are confusing the value of money with your need of it. Having more money cannot decrease the need for it unless the monetary unit maintains its value.
I'd disagree, there are varying levels of scarcity so there will be varying values. Someone could be wealthy in a poverty stricken country with a hundred dollars and have way more than he needs but could barely get through a week with that same hundred in the US and the same situation exist everywhere, Jamie Dimon will value a thousand dollars far less than whoever cleans his office.
You keep confusing the need for money with its value. The value of money consists in its buying power, not in how much you need it. Of course, if you have the amount of money Jamie Dimon has, then you can indeed change the value of the monetary unit, despite certainly not by just needing less of it.