Yea, they all suck that way. I still use my own router for wifi. It’s just routing, and your own router will know which way to the internet, unless there’s something I don’t understand about your internet connection. See my other comment below.
Yea, requirements mapping like this is standard stuff in the business world, usually handled by people like Technical Business/Systems Analysts. Typically they start with Business/Functional Requirements, hammered out in conversations with the organization that needs those functions. Those are mapped into System Requirements. This is the stage where you can start looking at solutions, vendor systems, etc, for systems that meet those requirements.
System Requirements get mapped into Technical Requirements - these are very specific: cpu, memory, networking, access control, monitor size, every nitpicky detail you can imagine, including every firewall rule, IP address, interface config. The System and Technical docs tend to be 100+/several hundred lines in excel respectively, as the Tech Requirements turn into your change management submissions. They’re the actual changes required to make a system functional.