Changing passwords, keys, may help to an extent. However, Apple and Microsoft and Android computers, phones, devices, have back doors. So, it is possible for people to find your new password for example.

I use Ubuntu, which is a Linux operating system (OS) that is said not to have back doors or certain vulnerabilities like the others do have. Twitter told everybody yesterday to change their passwords. You can see why.

To really keep passwords safe, it has to be maybe encrypted. I use Firefox which saves passwords in a password manager. So, that manager may be hackable perhaps.

I keep an offline Electrum Bitcoin wallet and that is more secure. If somebody can get into your computer, then they can probably find your passwords. So, it is a matter of how safe you may want to be. It all can be overwhelming for some people. But I do like what you are writing about and your goals in helping on Steemit.