"I should be able to attack all the world" I'm guessing they want to be able to attack everyone who is on the same server.
I am kind torn here as personally the neighborhood change was awful for me here at beta but I'm hoping it works out better in the main servers. However, I would agree with the fact that if all things go well, 80 players is indeed too many. If you are in Industrial Age then with this new neighborhood system you will eventually have only members nearby your in the tech tree --- all of those 80 would eventually become Industrial (well, PE by that time). The 80 players thing seems rather easy because most players have it easy --- 3 to 5 top players, about 10 to 15 medium active, and all others in the hood barely progress and are the easiest possible target. So, it seems like even 80 just isn't enough.
But that's basically because neighbors currently aren't working as intended --- if you're in the same hood with 80 other players who are at the most one age below you, you won't be having fun with that many players. It'd be too darn stressful in my opinion, or at least for the heavy PvP folks.