1 - Where does AirNav say that they will pay for all shipping costs?
Apparently in the contract Airnav have with (at least some) of the people volunteering to run these "free" boxes, according to Drazick who has been accepted into the program, and would have signed the said contract. Being asked to pay 60 € for a "free" box doesn't sound like what was offered to me.
in the contract with AirNav systems, they become responsible for all shipping costs
I guess its Airnav's call - they can pay the duties and get coverage in the Canary Islands, or the box can be returned to them.
3 - how many users would only pay for internet access because they had a RadarBox?
Not sure about where you live but we don't have unlimited internet here - there are quotas, and if you have a device uploading 24*7 then it will be eating into your allowance. Its not nice being capped when you go over your allowance.
4 - the cost of a RadarBox equates to an awful lot of electricity, and many users keep their boxes on 24/7
Most people don't leave their computers running 24*7, so doing so would add considerably to their electricity bill - possibly a few dollars per day - multiply that by months or years and the additional costs would be considerable. The radarbox hardware doesn't run without a computer and software.
5 - Do you have a qualification in gift-horse mouth inspection, or do you just do it as a hobby ;-)
Well I could have put my hat in the ring for one of these boxes, but I didn't because I don't see any benefit to myself, only additional costs and inconvenience.
Sorry if you don't like my opinion, but that's what it is.