Regarding the separation of investment banking from retail banking, I am strongly in favour of this.
However at the moment, investment banking subsidises retail banking quite significantly, if you change this then banks will start charging for retail accounts.
There are a couple of solutions to this, but they all basically come down to the same thing, someone has to pay for the retail banking. Either it comes directly from the customer as a periodic payment or it is funded by taxation, I suggest the later because arguably a retail bank account is a necessary part of modern life in the west and could be considered a utility.
I would personally like to see retail only banks that charge and are strongly regulated to avoid bailouts in the future.
Investment banks should be allowed to offer retail services, but they should be forced to make it clear to the customer that if their investment arm fails, there will be no bailout from the government and they could lose all their money.
Let the people who want to play roulette and let those that don't have an option too.
Sadly this kinda depends on their being enough consumers who don't want to play roulette.