One question... Imagine that I've put an account at sell list... after 4 years, if no one has bought that account, I will lost it or it will be at sell list forever?

u'll lost only coins (if acc isn't empty), acc remains urs.
Not correct, the account with funds are reclaimed.
Are there any other ways an account can be reclaimed by the network? What happens to the account once it's reclaimed?
According to current protocol when an account is not modified (no transfer funds, no receive funds, no change state...) during 420480 blocks (aprox 4 years) the account balance can be claimed by the miner,
BUT only the balance, not the account.
The original question was what if an account is listed for sale, but never sells and that person dies, or whatever. Is it for sale forever? What happens to the account that is listed for sale for more than 4 years?