Auctiva should be used as your "Front End" for listing and then some. I just started using it the other day and have learned many of the in's and outs.
First thing to do is create your shipping profile, payment profile etc. and save each of them preferably under a common name. I for example called them "StandardShippingProfile", "StandardPaymentProfile" etc...
Then you create a "MASTER PROFILE". In that master profile you include the above profiles created.
This Master Profile will be used when you create listings.. I called mine "StandardMasterProfile"
You can create all sorts of them for various things. So for example lets say if your selling Rare Coins you might not want your standard ship terms, you might demand insurance or ship these only via FedEx whatall... Point being you can create various profiles to handle your various circumstances of products/listing differentiations.
Next... Set up your images directories.
Make sure to carefully examine every display Auctiva presents as there is quite a bit there and in some cases such as combined shipping issues you need make sure you read what Auctiva says.
Once you get the hang of things it's pretty slick. There are several things I'd like to see added to the service thus far that would make it more flexible. But it's really nice.