I definitely only have one database so far, with two tables--one has my membership info and the other is the users table provided by Webassist. So duplicate users tables is one of the few problems I'm not having right now. I just asked the question (about whether I should have added their table to my own db) because having a preexisting database wasn't addressed in their documentation.
One thing that confuses me about my root user password issue, is that after I set it, then try to access mysqladmin on my computer through the browser, it doesn't give me a login screen, only the access-denied error message. I'm using the latest version of Firefox and thought, maybe I have popups turned off or something, but no, that wasn't the case. Do you see a login screen when you try to do the same? If not, I'm assuming it should just automatically open the application, but it doesn't.
I will get back to this Monday and what I may do, if I continue to have problems, is what you suggested - dump all these files, do a fresh installation and configuration, and then see where I'm at.
Thanks enormously for all your help. Will post back.