When inserting a youtube video url in a bbpress post, the video is not well adjusted, that is a part of the video on the right hand is not visible and there is no right margin at all. It is theme-related, because I tested with two other themes and I dont have this problem.
I tried with code integration (not just url insertion). In this way, dimensions are adjustable (inside the code) which can resolve the problem with medium/large pc screens, but not really with small screens of pc, tablets, smatphones. It is not esthetically correct to have very small videos to insure they are visible in any device. So the problem is mainly lack of responsiveness. Hope the new version of Firmasite fixes this issue.