1. There's nothing stopping you from shoving the library code onto a thread. For something like this request-response style usage pattern, that sounds extremely straight-forward, especially since the previous paradigm was probably an async server anyways. The calling code (from the editor) obviously already had to be support async calls, so no real change there.
2. If $LANGUAGE can be used to write a server, it should be able to build a DLL. I realize this is not practically true, but I also don't support the notion that we should be writing even light systems stuff like this in JS or python.
3. lol. You're telling me you're worried about a process eating 32GB of ram parsing text files ..? If some core part of my editing workflow is crashing or running out of memory, it's going to be a disruptive enough event that my editor might as well just crash. The program I'm working on uses a lot of memory, my editor better not.
4. I guess ..? Barely seems like that's worth mentioning because .. counterpoint, debugging networked, multi-process programs is massively harder than debugging a singular process.
5. Why would I want (other than extremely niche applications, shadertoy comes to mind) an editor to run in a browser? If I have a browser, I can run an editor that connects to a remote machine. Furthermore, the `library-over-http` approach of LSPs doesn't really buy you anything in this scenario that using a single process wouldn't.. you can just send all the symbol information to the browser.. it's just not that big.
6. Wut?