need to know if it is a patch or a configuration to separate the rokgallery component form sharing its php.
It saves information about imagery int he media folder which is commonly shared but you had created a patch for Zoo to avoid similar issues.
Currently if we delete an image form one slave site or the master it creates an error and freezes the site. It is also impossible to delete images once they go missing from one site.
If you can estimate the extra time to help us repair this link or possibly create the necessary patch that would be great.

I also need to understand if adding virtuemart will require any special mods as we may need to offer individual shopping carts with no common products and also as a gateway for payment through Jevents RSVP ticketing.

If RokGallery save the images in the "media" folder and that you want to have a specific "media" folder in each websites, you need to create a JMS template rule where you specify that you want the action = "copy" for the "media" folder. By default this is a "Symbolic Link" and therefore shared.