Can I but "bookmarks" in Thunar?
 

Is there any way to put certain directories along the left-hand panel? Or something? For example, there are some directories that five sub-directories deep, but I go to the directories often. I would like a one-click operation to go those directories.

try doing a right click on the folder you want to add to your bookmarks.
i use thunar in ubuntu and when you right click the folder, a menu opens with the option to "add to bookmarks"
then it goes in the sidebar

hope this helps

Seems to work. Thank you.