AlienMind: You're talking about things Microsoft can switch off any time they want to, and I believe they will, after a big number of applications is packaged as UWP. You have to pay any fee Microsoft wants to as you can't make a running binary anymore without a certificate from Microsoft. That's called completed Vendor Lock In, like Apple (and a bunch of Gaming Console Vendors) has/have almost achieved.
You can only trust FOSS, guys. Preach out.
And even if they did, I believe if GOG or Steam really wanted to they could release UWP client in the store and sell UWP games that way. Same way MS is allowing iTunes, Amazon Music, etc in full to come to the Windows 10 Store and sell music and movies.
My understanding is, MS only takes a cut if you use their built in store payment system that is offed to developers. If you design or include your own payment system inside your app then you can release products without giving MS a cut. I could be wrong, but that is what I believe I read somewhere.