1. Multiball system. It takes so long to resume play if someone kicked the ball into the stands!
2. Referees should be able to be punished for fatal mistakes, especially in bigger tournaments, so when you criticise the ref and replays show that you're right and the referee's wrong, instead of staying silent FA should suspend the referee for some amount of time or matches.
3. FIFA Manager of the Year and FIFA Puskas (Goal of the Year) awards would be nice stuffs to add.
4. Ability to negotiate sponsorship deals, rather than just given at the start of the season.
5. Ability to set ticket prices, at least for bigger matches.
6. Ability to expand national stadium. It's not nice if you manage a national team who plays in a small national stadium that no single club uses as its homebase and you can't expand it when you start achieving more with the national team.
7. Every nation should be able to propose a host bid for major tournaments once they meet the infrastructure requirements (for World Cup, for example, any nation should be able to bid once they have 10-12 stadiums with 40000+ seats, 1-2 of them 80000+ seats, completed or to be completed before the World Cup date), instead of seeing the same countries bidding over and over again. And if you are a very reputable manager and your country is making a host bid, then you should be able to back it.
8. New rivalries that could form within several years. For instance, if you manage Rotherham United and went on to reach the Premiership and are on a title race with Arsenal then Arsenal should be Rotherham's new rival, especially as their home shirts are almost identical.