Yes you can configure JMS with Virtuemart 1.1 on goDaddy.
Godaddy linux delux plan and unlimited plan are working perfectly.
You can effectivelly have different website that share the same VM products.
You can share the master or share another slave.
Concerning the payment method, by default VM save the configuration in file on the disk.
Therefore all the website will have the same "paypal" email account.
This is also true for all the payment method.
If you want specific merchant account or paypal email for each website, we have recently published a product that patch the VM 1.1.x payment method in aim to have a specific configuration per slave site.
www.jms2win.com/en/joomla-multisite?page...49&category_id=1
I suppose that the 4G unlimited replace the "unlimited plan" and that should work.