My somewhat educated guess here is that you're going to be running around in
Dependency Hell trying to round up and install dependencies that PeerGuardian requires to run on Zen.
> ...libpolkit-qt-gui-1.so.1: cannot open shared object file: No such file or directory
This error above is telling you that a req'd library file is not being found on your system. That's probably just for starters. If you resolved that error, there would likely be more following. That's Dependency Hell.
I could be wrong about this because I'm not familiar with PeerGuardian and I haven't run Zenwalk on any of my systems in years. Please stand by for further assistance from others with more knowledge on this topic/issue. Oh, and SEARCH, SEARCH, SEARCH (DDG, Google, whatever your fav) online. You might find others with a similar issue that has been resolved.
Luck! Sorry I couldn't be more helpful.
~Eric