Great find, planes!
I've used this page many times to help me fill up my titles with the best keywords, and I often give it out to clients.
I would, however, like to clarify a couple of things from your post:
First, this page, while extremely helpful, is not a listing tool. A listing tool is a program or website you can use to create your entire eBay listing or at least your entire item description. Instead, this would be considered a keyword or market research tool.
Secondly, although eBay's default Best Match search sort is based PARTLY on keywords, it is also based on many other factors, including seller performance and reputation (feedback, time on site, DSRs, disputes), pricing, format, category, shipping cost, etc.
Another interesting thing to question to touch on what planes was saying. How about when you use that import listings on other selling sites? like you know when you click to import listings from ebay to the other sites...if you go into your seller preferences you can see all the sites that are linked to your ebay account. I wonder if ebay is monitoring when they see your taking your listings to those sites if that will also effect your exposure on the site?