"No, this is Netherlands only since this is easier for GitLab Inc. to do. We have more team members in the Netherlands and we got accepted in the local European Blue card program years ago (after a business plan review by the government, it wasn't trivial at the time I remember)."
Normally a work visa requires a local "visa sponsor" or employer so Gitlab would only be able to offer relocation to countries where they have a fiscal presence.
Frankly, I can't provide a detailed answer to those questions.