Yes, you can link your P5 Library to external runtimes, even on other drives or removable media. jelisa wrote a tutorial describing the process shortly after P5 was released.

http://www.fignations.com/jelisa/tutorials/p5link.html

Netherworks posted a tutorial over at PoserPros explaining how to remove Content Paradise (or at least the tab) from Poser 5.

http://www.poserpros.com/forums/viewtopic.php?t=16569

Make certain you download and install Service Release 3 from Curious Labs; it fixes a lot of problems, improves performance and stability, and only adds a couple of new bugs.