eBay doesn't want you to move your listings to other sites. If you want to download everything, including photos, you will need to subscribe to a third party listing tool.
eBay has a reports function, accessible here. You can download a CSV of the criteria below. It does not include descriptions or item specifics. There's a way to download item specifics from the active listings tab, but it will only pull in listings missing recommended or required IS - it won't pull in listings that aren't missing any IS.
Summary of Listing reports columns:
Item number
Title
Variation details
Custom label (SKU)
Available quantity
Format
Price
Sold quantity
Views
Watchers
Bids
Listing site
Additional columns
