Lots of great questions and i am sure that you will get some interesting responses. I don't think anyone has had any success in forming an intentionally-Epicurean community in modern times, but it's a topic that is frequently talked about, and I agree with you that it is doable. Now that we have the internet to bring together people who would not normally have been able to find each other in the past, things like this become more possible.
Probably you would need a "leader" to ultimately make decisions on most of the issues you raise, but over time I would think that groups who share similar viewpoints would be able to pull something together. It's a big hurdle though -- as you will see here, even where we make a strong effort to keep things within defined boundaries there are many different opinions as to what is essential and what is not. I expect that there's no substitute for time and effort and it will not be soon, but it will be possible, for a critical mass of people who see things similarly to make plans on closer association. All the issues you raised have to be addressed first, and there will be lots of differing opinions on most of them.