There are lots of questions here, but almost no answer. Maybe the community manager should pay a bit more attention to this thread...
Unfortunately, they doesn't give a lot of informations about their work. They are just saying "Hey, it works!", but we cannot say if it's true or if it's false. Nobody know, except them of course.
They are claiming that the next version will be open source for a while, I hope it will be. And soon. It would finally bring a few answers to our questions.
if I want to browse the web on the sub network for free I need to run a node. Right?
To bring an answer (one of the very few questions we can answer...) :
The people browsing on the sub network would do it for free. I guess that you will need a substratum client or something, but you would not need to run a node. The people that runs a node are the ones that hosts the websites.
The sites' providers would pay the nodes to host their websites, not the visitors (like any site on the classical internet, in fact).