I think I like pretty much all the recurring features. They all have their own unique charm. The Rocket League one might be the weakest. Game is not really set up well to spectate at this point and the game is so concentration heavy that it just leads to boring trash talk for an hour. With only 2 episodes, I'm not sure I'd count it as a regular feature yet, though.
Sure. I just found the videos really boring. Everybody on screen was playing so nobody was doing anything except enjoying the game. Which, I mean, great for them and all. But from the viewer's perspective, it's not any more entertaining than watching good Rocket League play.
And as for Mario Party Party, nothing good has ever come out of Mario Party. It is a black hole from which good and happiness can not escape.