There is a lot of confusion about what hifi is. It works like the web. Domain servers/assignment clients are just serving content, like apache serves html.
I think people are inclined to think HiFi is a complete solution like Second Life, when it is not. HiFi is more like Network Solutions mixed with Mozilla, a marketplace and (soon) Blockchain. Interface.exe is just something they made because it is needed and it is all open source. For all intents and purposes it is a VR browser and nothing more, while High Fidelity is providing a range of services to support it.
Yes, it does perform authentication with hifi servers and yes will be tied in with a wallet, and yes hifi servers are hardcoded throughout it. Personally I think hard coding these things is a mistake and may hinder its growth but it is just a matter of time before somebody comes along and converts all this code to run their own network (or even converts it to run on any “hifi” network or allow selection from a range of different service providers who specialize in things like authentication, cryptocurrency, domains or what have you).
Anyway I think referring to interface as a browser could clear up a lot of confusion about what hifi is, after all that’s pretty much what it is and calling it a browser will give people a better frame of reference for how to view it.