If Manchester United build their new stadium, it will have a capacity of 100,000 people. That would be a huge financial income for them. Old Trafford will become New Trafford. 
Maybe with the new stadium they will be a team that will fight for the championship again. Right now they are far away from that. Especially this season their position in the league is embarrassing.
Agree with what you said, for now Manchester United is not doing well, when will their curse be gone, for the past few years they have not been able to rise again like before, losing continuously, to Manchester United lovers must always be patient and willing to accept all these tests from their proud Club, because they have tried their best, maybe their fate is only up to that. Maybe with the new stadium they will be a team that will fight for the championship again. Right now they are far away from that. Especially this season their position in the league is embarrassing.
For now the highest points are still controlled by Liverpool and followed by Arsenal, between the two clubs one of the clubs that is easy to replace is Arsenal, because Arsenal has points that are not much different from Nottm Forest and Chelsea, both have points that are almost close and slightly different, it could be that they both will change Arsenal's position from second place to 3rd or 4th place.
Sure. Liverpool are leading the standings currently, and as you said, Arsenal are second in the table, although I don’t think Arsenal will make any mistake that will make them drop points and leave that position to Nottingham Forest right now. I think they would rather do more and see if they can be able to near Liverpool in points, but I don’t think they can surpass and get the first place in the table currently; it will be hard for Arteta to get it.
I think they should just maintain their consistency, and if they can’t improve, they should not drop in performance so they won’t lose their position to Nottingham Forest. And I think Arsenal are not too bad to make that happen. Let's see what they will do; there are still matches to be played, and we will see what Arteta will do because he already knows Nottingham Forest is going to be a challenge for him in that position.