As for their first game, I don't think they can win against Arsenal. It's probably they lost it.
Most people really believe that Arsenal is going to win Manchester United on week 1 of the premier league and I also feel that way too, but I want us to not write Manchester United off because they are a big club with history ,so don't be surprised if we don't get the desired results.
I see it as a tricky game for Arsenal, traveling to old Trafford for there first match of the season, even if I am about 70% sure that Arsenal will win on the day, but we all still have to be cautious, because it's the first match of the season and anything can happen.