Hi there Nik!
1) Yes the matches on the IC will be played against other Managers. The match time will be decided once the draw is made.
2) The International Cup will repeat three times. You can only pick your national team once and play all the tournaments, however, winning it multiple times will bring increasing and some amazing rewards!
3) Your IC opponents will have different qualities. The IC is a prestigious Top Eleven competition - make sure to prepare your team well!
4) Once the IC starts you will not be able to go back to the Preparation Phase however you will be able to buy new players and improve the team by training.
5) You can play each country multiple times during the Preparation Phase without tokens required.
6,7) The IC will have 32 countries divided into the groups of 4. Which means you will be facing 3 different countries in your group.
Hope I was able to answer your questions

Good luck!