Yeah, maybe not completely useless.

No, infact sync would make the moderation system useless. I think there is going to be both advantages and disadvantages with this approach. One big disadvantage is differentiating the communities because users would be expected to check the server name.

I also have a lot of questions regarding how same communities on different servers would look like. There are already 2 c/technology communities. Are they totally seprate or the data is synced between the two?