Your computer. This isn't much of anything to worry about. Any competent tech person can remove the passwords so others can get on. I know that isn't comforting as to your safety of information but it is true.
Everything else is far more difficult. It involves breaking the first rule of security "don't share your password." Of course that begs the question of, who do you trust? And if you do have someone, how do you give them everything they need? Here are some of the options that make things easier:
Last Pass is a program that allows you to store all of your passwords and personal information (bank numbers, credit cards, etc) in a place that is accessible from any computer. Assuming you use a very secure password for the site it is a very secure program. The difficulty with this is, if you place your trust in the wrong person they have complete control.
Place a document in an obscure place on your computer that has the information or the password to a program like Last Pass. Let that trusted person know the name and location. Don't name it anything obvious or enticing to look at. Something like garbage, or temporary would be something that the average snoop wouldn't bother to read. If you have a backup make sure that it gets this file as well.
One more choice Deathswitch. This program sends you emails at what ever schedule you choose. (daily, weekly, monthly, etc.,) If you don't respond within your set time you chose, it will email your instructions to the person or people you chose.