ugh, in the thread you link to, Sunny King sounds like a "disincentive for pool formation" is a good thing. I disagree, a minting pool will be needed, and it would be great if the pool could work only with the minting key and without actually requiring users to deposit. If there is a PoS block every 10 minutes, but after 90 days as time passes wihtout minting you start to loose interest, then there won't be enough room for everyone to mint and earn their full interest. So only those with high stakes will be able to do it, creating further inequality in the system.
I think the minting pool will cause a bigger problem than inequality, the 51% attack, if the minting keys are reuseable.
Since leaking the minting key does not do harm to the users' coins, the users will tend to share their keys with others easily(move from one pool to another, etc.), which makes it easy for attackers to collect minting keys. If someone collects enough minting keys, they could do 51% attack easily----the attack costs really little.
If we want to avoid such attacks, we must require most users to change their minting key regularly, which I doubt will work smoothly.
So a minting pool seems to be unrealistic without significant changes in the cold minting strategy IMO.
For the margin interest problem, maybe we could alleviate it by lower the hardware costs, such as mobile wallet, lightweight wallet, etc. If the hardware cost is low enough, most users will be able to mint with good interests.
