Hello,
If you are so paranoid. Why would you use a hacked password in the first place? Plus i have already pretty much answered your questions.
They can keep the logs as long as they want. I know some places that have their logs from 2004. I know places that have their lgos back from when they started their website. Each site is unique as to what they do. We can answer cause a.) we dont know what website. b.) we dont know what their poliies are c.) we dont know what their admins do as far as tracking.
So as you see you cant really have a answer to your question cause we are not the sites web master. Sorry but you will never have the answers you want unless you contact that sites webmasters.
Cheers,
Mak