same or similar result for:

  https://www.google.com/search?q=%27%27
  https://www.google.com/search?q=%22%27%22
  https://www.google.com/search?q=%22%20%22
  https://www.google.com/search?q=\%22
  https://www.google.com/search?q=%22%22%22%22%22
  https://www.google.com/search?q=;;;
  https://www.google.com/search?q=...
  https://www.google.com/search?q=,,

For all of them, I get a simple "0 results found" page. Does anyone see something different?

From a swedish ip i get only this video https://youtube.com/watch?v=CPxCuJD1Uy4 Which discusses a report from the swedish internet foundation about internet habits

For me it only shows two results, and they are both to https://m.youtube.com/index

What do you see? I get no results at all (Chrome/Android).

It depends. If I'm on VPN to e.g. Belgium, there is exactly 1 result for https://www.encyclo.nl. Without VPN I get 2 YouTube playlists and a single Facebook post. In incognito mode I get no results.