I find that when I use the auto classify option, I don’t know how to find out where in the world DT dumped my document unless I do a search. Is there any other, easier method because search can sometimes stall when my computer is bogged down.
Is there also a way to find replicates or duplicates of a selected document without using search?
I like your questions. 
Not sure how well it’ll work with auto classification active, but one (limited) way to locate items without searching is with the History window (via Tools->History menu). I’ve been formulating ideas for improvements to it but I’ll save that topic for another place and time.
When you’ve selected a replicate (but not a duplicate) you can use Next/Previous Instance (under the Go menu) to navigate between other instances of it. Last I checked, a search only matches one instance of a replicate or duplicate; there’s no way to easily locate all of them when they’re in different groups. I put that shortcoming in the same category as the lack of comment and label “instances” searching as I described in another post. I can remember getting a response when I first mentioned it so I’m glad you’re bringing it up again since it begs explanation.