A few questions on branch protection rules

Hi, I’m looking into some branch protection rules for the main branch in our repository and had a few clarification questions that hopefully someone should be able to answer.

  1. Restrict who can push to matching branches

By enabling this rule, does this mean that only authorized users or groups would be able to merge an existing pull request into the protected branch? The scenario I’m hoping to create is: user makes a PR against a branch and passes all the required status checks but we want to further restrict the actual merging of the PR to a select group of people. Is this what this rule is enabling? Also, what does “matching branches” refer to?

  1. Require conversation resolution before merging

Based on your experience, is there any downside to enabling this rule?

  1. Require a pull request before merging

Based on your experience, is there any downside to enabling this rule, especially if there are 10+ contributors to a branch?