I've just begun looking into multi-language options as well, particularly for a recent project I have been working on that I think could really benefit from it. In particular, I am looking at ways this could perhaps be done without stuffing everything through P2VR.
The first thing that has struck me is the XML format of a tour's main XML file- This could easily be parsed on-the-fly with an additional PHP script (if one is accustomed to coding PHP for various web related stuff that is) that could swap out the various elements using text with their corresponding translations stored in a sort of template or master-file for all text instances used in the tour and found in the main XML.
The skin.js file is another matter.. Text used within the skin are buried within the .js code and thus not easily parsed. Perhaps the "CSS-Classes:" field for skin elements could be utilized to id these elements for replacement/substitution via CSS? Same with the images perhaps? Worth looking into I think.
I am relatively new to P2VR and am finding P2VR's usage of XML, JS etc. at it's core very intriguing, and very much full of possibilities that are just barely touched upon in the P2VR documentation.
Example: I was editing a text file and pasted what I thought was a line of text from another file, but instead it was a whole chunk of XML.. Upon closer inspection I realized that it was a "skin element" that was still on my clipboard from working on my P2VR tour earlier. Did not realize that P2VR skin elements were basically just chunks of XML being pushed around in that program. Very "Unix like"
Is P2VR originally written on Linux btw?
Which led me to think about things like: generation of skin elements on the fly via scripts and database records? Yeah, that could be pretty cool actually. So much to consider and think about