Again, pcmanfm seems pretty good. It already looks more stable than last time I tried it (of course, it receive many fixes). Did every thing I asked it and never crashed.
One minor thing (that maybe isn't important) is that it comes pre-configured with 'gksu %s' for switching to root. gksu, AFAIK, is a Debian app (maybe other distros use it), and here in Fedora we can use 'beesu' in its place (or in other distros one may use 'ktsuss' etc.).
The other related issue regards the desktop handling (beware that the text below is quite convoluted because I wrote while experimenting with things).
I'm using Xfce (without xfdesktop). It has a setting to enable/disable changing workspaces with the mouse wheel (/general/mousewheel_rollup property toggled - true or false - with xfconf-query, just to mention, true is default).
If pcmanfm is handling the desktop, then this Xfce setting doesn't work, regardless if it's set to 'Show menus provided by window managers when desktop is clicked' or not.
It's been a while since I used openbox, but, correct me if necessary, IIRC pcmanfm toggles the desktop with the mouse wheel even when it's handling the desktop and openbox is the window manager.
I know that xfwm uses standards for this because we can use wmctrl to manipulate it (and change desktops, for instance).
I thought that if possible pcmanfm, say, if it's handling the desktop and 'Show menus provided by window managers when desktop is clicked' is set, then it would send inputs to the window manager like if there was no desktop window.
But as I said, I don't know how Xfce (xfwm4) implements that feature of changing desktops with the mouse wheel.
What maybe could be done is that pcmanfm would have a similar option in its advanced section of desktop preferences of enabling/disabling desktop switching with the mouse wheel and it would send the proper inputs to the window manager.
pcmanfm recognizes the current workspace properly as it sets different wallpapers fine.