I've heard the analagy used that "Servers are to Serverless what wires are to wireless", the main point being that they're still there, but they're no longer something you manage or directly interact with.
I'm also starting to see the term LaaS (Logic as a Service) used as an alternative to "Serverless" here and there.
Your summary does not accurately reflect what the license states.
You can use Visual Studio Community Edition for commercial programs, so long as:
* You're not doing so for an organization that has more than 250 PCs or 1 million USD in annual revenue
* No more then 5 users in the organization that you are using it for are using it for things other than open source, academic research, and classroom learning
I don't know the answer to that myself unfortunately. I know the entirety of the runtime itself is OSS and when you do local run/debug of a Function it's the same runtime that Azure uses.
It's not an apples to apples comparison though since OpenWhisk is intended to be self deployed.
I mentioned Functions here just because many folks don't know that most Azure SDKs, runtimes, tooling, etc are OSS by default.