I have a big prejudice against Arsenal so I wouldn't place a money bet. The odds don't look that attractive and Arsenal look so unreliable.
Regarding the second game, all outcomes look attractive

Good risk and good reward, either team can win. A draw is also possible, I expect Nottingham to keep the game dry, so something like 0-0 is very likely (although I'm sure the bookies are quoting BTTS Yes as clear favourites).
That's the same for me because in the current conditions taking some bets on Arsenal is a bit of a risk so it's better to hold off.
For other games like Manchester United it's the same because the performance of this team when facing a much more balanced team is difficult to predict and there is probably a lot more potential for a draw.
For the current position I won't bet because it's difficult to make predictions because both teams playing will try to do their best so it's difficult to predict.
Although Arsenal is at the second position of the points table of the English Premier League, the performance of Arsenal has not been going very well recently and we have seen that in the last few matches Arsenal have faced against Manchester United in the English Premier League, Arsenal have not been able to secure a win. Betting on such matches should generally be avoided as the result may go against or result in a draw. There are many more matches in the Premier League that if you bet on a particular team, there will be more chances of that team winning, I think you should bet more on those matches. As Arsenal and Manchester United are the strong teams in English Premier League then we have to keep an eye on the performance of these two teams and if there is a change in the performance of the two teams then we can think about betting on these two teams.