I somewhat agree with you that a monetary system should not create an artificial growth, though this is a separate and very complex topic in itself, with arguments both in favor and against such growth. But how does it challenge my point that the elites are also interested in the common good over the long term?
It doesn't. It's a totally separate issue. The elites are only 'interested in the common good' in the sense that they want their bubbles to be sustained for as long as possible, because they benefit the most from these. But the way they go about it, and the incentives for the elites to destabilize their own system, guarantee that the bubbles will burst, with the worst pain suffered by the public. They either don't see this coming, or they don't want to see.
Besides, the problem with a limited-supply monetary system is that it heavily interferes with the economic growth. Basically, money should make economic relationships easier or, at the very least, not stand in the way. However, a limited-supply currency takes away some percentage of economic growth as it rewards holders for just holding that currency.
It doesn't. It merely allows savers to retain their honestly earned wealth. Deflationary pain in the past has simply been caused by the collapse of the demand that has been propped up by the economic distortion from financial inflation during the 'good' times, in the first place.
But if you reward someone, you should necessarily take from someone else. There is no free lunch. In this case you take some share of the revenue from producers who are actually doing something useful and give it to someone who doesn't do anything productive, who does nothing apart from sitting on their money. Why should they get rewarded?
'Reward' has been made morally relative in your argument. When you take morality out of the issue, you can argue that when you prevent the theft of a wallet, you're rewarding the owner of the wallet and robbing the thief. Oh, and if the theft promotes economic growth, so much more power to your argument. (Not that I'm equating your argument with this -- I'm only saying if you give no consideration to moral issues, you will reap your 'reward.')