Suggestions, International Management.

[GreatMarinho]

Tactics, training and Team Dynamics:
National teams usually have less time for training and tactical preparation compared to club teams, plus the players have a long season in their bones. That's why the focus of national team training should be on tactics, regeneration and player chemistry.
National team players often have less time to build team chemistry. The bond between the players should be strengthened through friendly matches and a well-chosen training camp. It would be very important in this respect to have a well-coordinated axis. Example, "The Bayern Axis" in the 2014 German national team.
In order to build up your Team, you should be able to set your National Team players, so you only need to remove them when they are Injured or the Form is bad. So you can build up a real Team spirit.
Team Cohesion or Team spirit is probably the most Important thing when It comes to a National team, remember when France were sent home without a win at the 2010 World Cup? When Domenech and Anelka had a big dispute. And all the French players were annoyed by Domenech?
Or when Germany won the World Cup in 2014 the players said that the Team spirit they had was very special. So it should be one aspect you have to manage which should also influenced by Players personalities, attributes etc.

Mentality and motivation:
Players who play for their home country can feel additional motivation and pride. With the right player interactions, you can get the last percent out of the player, which can make the difference between victory and defeat in a World Cup knockout game.
More interactions with players - for example, let's say there is a young Player you want to test out. Atm, you just play him and that's it, even if you left someone like Kimmich on the bench. But in reality Kimmich would say "What are you doing?!" so why can we talk to a player before the nomination and tell him that he can have a break, and you wanted to try out a new player, but he shouldn't worry about his place in the National team. Which makes more sense in my opinion because, atm, if I do not nominate him he starts crying.

Scouting opponents:
You should get detailed scout reports like in club management, with strengths and weaknesses of the opponent. Tournament management:
Very important in a tournament is the mood within the team, here you could also improve the mood of the players with interactions or special team measures or not.

Short; long-term goals:
Unlike club teams, which you can build for the long term, the aim with national teams is often to achieve short-term success in tournaments. In this case, there may be guidelines from the association on how to achieve short-term success with a long-term philosophy or where the national team should be heading in terms of play. Interactions with the Association President + Visions could be added. Same with Fans opinion as in the Club management. 

Budget and prize money:
A national team should also have a budget for the coaching team, scouts, physio etc. You could also introduce something like a soccer academy, which could be upgraded in order to train the staff better, just as better NewGen staff could be generated. And the higher the budget, the better a training camp could be booked before a tournament. So you can invest the Prize Money in the Nation's football infrastructure. 

The Abschiedsspiel:
In Germany, we have something called "Abschiedsspiel" lets say Müller decides to retire from the national team. Let us then arrange or declare a game to an Abschiedsspiel where your retired player can play one last time as a captain and then is done. Also, that should only be available when a player has played over 100 games for his nation. That is very different to a Testimonial, which is in FM.
This could also be added for club management if a player decides to retire. So when a player has more than 300 games played for the club could get an Abschiedspiel to say farewell to the fans, club and football and then retire like Oliver Kahn on 2nd September 2008.

License:
Last but not least, you could also secure more licenses, because the more licenses the better. But of course it's a tricky thing with the licenses. But a FIFA license with continental licenses would be cool.

I really hope that with FM25 we finally get the improvement of International Management that FM deserves.