Credentials for site are confusing

I’ve been a customer of Dreamhost for almost 8 years and let me first say that for the most part you have all done an excellent job! However, one thing I have found very difficult and confusing to manage are the various ways to get authenticated for the various features an account offers. For instance, I created a new domain, registered it and activated it and was reminded of the difficulties. I had several choices of usernames to assign to /root, I had new choices FTP login credentials which stopped working and when I changed it it worked gain except now my webpanel credentials were still using the old password. Getting into the the various management sites and which credentials to use is and has always been a weak point int he service. Anything you can do to make this easier, whether it just be a map of which credentials work where and why or merging credentials or some master credentials might make things easier. Thanks!