Thank you for your question.
The streambox.net FAQ has been drafted very cleverly. The true position is that, whilst a box like this, and presumably the one you intend to manufacture is quite legal and people can use them, many of the sites which are actually streaming the movies and other content are in breach of copyright as they don't have the copyright owner's permission to stream the movies. Netflix and Amazon and the like pay licence fees to copyright owners, however many sites don't, and there is an emerging industry of companies which are tracking down and taking legal challenges against the sites which are simply stealing
copyright content from owners.
So it is not quite accurate to say that downloading is illegal and streaming is not. You have to look at the situation from the perspective of copyright ownership. If you own the rights to a film and someone pays you to grant a licence to stream the film from their website that is one thing. If that person simply takes the film and streams the film without the permission of the copyright owner then that is a breach of copyright and is actionable. To that extent there is no difference between illegal downloading and illegal streaming. The difference is that the end user never comes into possession of the physical product when streaming.
But the website is still in violation of copyright. It's just that the violation is not shared by the consumer as the law stands at present.
So your product is legal to sell as long as it has no association with the many illegal websites that simply steal copyright material and allow users to stream via appliances such as that made by you.
You will see what I mean about the cleverly worded FAQ if you now go back and read it again.
Happy to discuss further.
Please leave a positive response so that I am credited for my time.