I want to open pcmanfm and have it display the highest level view showing all of my system's drives. For example, in GNOME when you click on the "Computer" icon on the Desktop it opens up and displays the highest level view with all of your drives. Here is a pic for the example:
I might be ignorant or something but I really don't see the need for this as your devices will show up in the sidebar, if you want THE VIEW as in the screenshot the closest thing would be to go to /media (and that could be a link in the sidebar).
Other than that I think you are on your own.
For what directory to open you can not set newer (libfm based) pcmanfm to open at a specific path as far as I know, on the other hand you can specify a path to be opened on the command line and by using that in all available shortcuts I would guess that you can direct it to show the directory of your choice. No "computer view" though.