Quote fromI'm going to regret posting here... but, having skimmed your idea there's a major problem with it.
"Single server, because Mojang can afford it."
Yyyyeah... how many MMOs do you play?
Mkay... now think about how many of them host their own servers.
Got that? Good, okay. Now think about how many of THOSE don't charge a monthly fee.
Now if you manage to end up with a collection that holds atleast ONE game, ask "how long has this game been around?"
To be blunt, your suggestion would force Minecraft to become Pay to Play.
You won't really regret it but get a couple of flamers. >.<