Thanks for sharing your Directory Opus setup. I found it instructive how your workflow dictated your setup.
I, too, do not use the tree feature. I find it takes up too much screen space for the gain in folder access. I, too, prefer first level buttons for one click access. OTOH, I always use dual listers.
I appreciated the discussion of the multiple ways to open a tab. I am using the Home button, again.
If you want to see my Directory Opus setup, take a look at Source Menu for Directory Opus 13 - #3 by jinsight
If you want to get the most out of this with the least time, look at two toolbars, -Menu JEG.dop with 741 buttons and -File Display Locations JEG.dop with 184 buttons.
The toolbar, -Menu JEG.dop has a Move button with many ideas on organizing folders with Move.
The toolbar -File Display Locations JEG.dop can give you ideas on how to to get the most access points to folders and files in the least screen space.
Enjoy your addiction.