You’ve answered your own question with point 6.5.3.2 as everyone else has tried to explain as well. In my honest opinion, flying a visual approach with ceilings below 1500ft AND below circling MDA is not a very smart idea, especially considering the sorrounding terrain. Take it as you wish.
ATCos have gone to prison in the past for issuing visual approach clearances in less than optimal weather conditions, suggest you read
this article.