Hi fozzy,
In addition to kbalona's answers to questions 1 & 2, both of which are correct...
3) No, Auctiva only provides templates for your Auctiva store and individual listings, so they cannot be applied to your eBay store. However, our design department can create professional feeling eBay store designs according to your specific preferences.
If you are interested in learning more about the custom design services we offer, I recommend visiting the following page of our website: http://www.auctiva.com/designservices/designServices.aspx#
-Mike