You replied to my sale thread, so I guess you know I hosted it. The dongle setup can track about 150 -200 km easily and further if you have line of sight. Since I am near the airport, the climbing altitude is not much for the range but around 10000 ft was common for me. The local tracking is generally a minute or 2 ahead of what you see on the web and you can of course track private and military aircrafts which are filtered out on the website.
I had applied for the free dongle on Flightaware before I purchased the setup, but they didn't respond at all. I think you have to pay the custom duty as per their valuation. At the minimum, they would also expect you to be in the line of sight of the airport and of course the flight information should be worthwhile for them.