I have been wondering about how possible it will be for me to pass down my accounts as part of my will when I have not given the passwords to anyone since am afraid of thieves.
Just write the private keys/seeds for your ETH wallet and keep it somewhere where they know where you'll keep it.
Tell them that as long as you are living, they can't move it nor touch it. Put a note to that safety box that tells on how they can claim your wallet by giving out some sort of instructions of importing the private keys.
You can save your private key(s) in a Google drive
This is the worst idea, anything you stored online can easily be hi-jacked if its worthy specially with $$ on it.