[Linden home has tiers?]

Hi I recently became premium, and I'm thinking to get a linden home but will I pay for tiers? 

And if someone changes membership from premium to basic and has a linden home he loses it?

[I can't log in I receive a message saying: Login failed. Unable to connect to a simulator.]

Hi I can't connect to my account and I receive the message: "Login failed. Unable to connect to a simulator". So do I have to do?