The ones where I lose are by far the most educational to me. I'd say if you're going to post anything, losing games are the most important.
As far as your comments go. I don't know what other people think, but I think you should just be yourself. If people don't like your videos because of the way you speak, then they won't watch them (or if they troll you then they're just sad, sad people). I find your comments amusing, even though I can understand how some wouldn't. If you're frustrated, I think that's OK, because everybody gets frustrated when they play, especially in a game with such a large luck component.
In the videos I recently posted where I played against Donald X. (squee) I made no effort to hide my fanboyism. To make a video where I'm not being myself just to pander to other people would be dishonest and I wouldn't do it. So I don't think you should either.
If you want to get better, something I do is I try to never blame shuffle luck (even when it's clearly the culprit) and find other reasons why I lost the game (and even when I win, I still try and find ways to improve what I did, but that's much harder to motivate myself to do). I know you had a rough couple of games today and I'd be frustrated too if that happened, but I'm reminded of my 3rd round loser's bracket match where I lost. I'm extremely glad I posted those videos, even though I really didn't want to.
Anyways, my thoughts. Take 'em or leave 'em.