Solution to the Strange User File entries
After a lot of looking, reading, and experimenting, I finally fixed the problem of TBH creating an ungodly number of anonymous users in the User and Profile files. In the web.config file (the main one, NOT the one in the Admin folder) I changed the "allowAnonymous" value from TRUE to FALSE in the following line (it happens to be line# 80 in my file)...
<add name="ShoppingCart" type="MB.TheBeerHouse.BLL.Store.ShoppingCart" serializeAs="Binary" allowAnonymous="true"/>
<add name="ShoppingCart" type="MB.TheBeerHouse.BLL.Store.ShoppingCart" serializeAs="Binary" allowAnonymous="false"/>
I believe that's the change that solved the problem. So if you don't want your User and Profile files filling up with thousands of junk entries, there's the fix.
I must admit, I don't understand WHY Marco set it the way he did to begin with. So if I'm missing some purpose behind the original setting, feel free to tell me what it was.