1) How do I remove comments on the blog section?

Hello there, 1) In order to remove comments (at all, not only the ones that come from default, but to avoid the comments form overall), I went to Settings > Discussion and made a few tweaks there. it didn't worked. What to do to remove all comments to appear on the page? 2) Is there a way to force the theme to show thumbnails on related posts? I LOVE the design, I don't get Why the thumbnails do not show up on related posts...