This might be true on your forum that accuracy 62-100 is enough, but there are other factors that determine if a post will be hidden. Again I implore you to read this post which those factors.
I’m having trouble parsing your question here, but “Something Else” flags have never been able to auto hide posts, nor is this now true with the review queue. The flag types that can result in posts being hidden automatically are “Off Topic”, “Inappropriate” and “Spam”. Previously if you were TL4 they would be hidden in one flag. Now, it depends on the score that is calculated.
No, sensitivity affects how strong an action is (ie, how many people performing it is required to do something like auto hide.) It does not affect the count in the red circle, which is affected by review default visiblity only.
This is a good suggestion and I’ve updated the text to be more clear:
https://github.com/discourse/discourse/commit/5981678abd7793b281e7352c4857e603d2803418
Perhaps you can explain how I could improve this post as it lists all the factors involved in scoring posts and I think it’s quite clear.