Some things:
1) You do not need a team as the commish, so you can sit back and watch.
2) League totals still work the way they did before. There is no way I can code it so that you type in the desired final stats, and the game delivers these. But there are now modifiers. So when you want 10% more homeruns, enter 1.100
The game does the rest for you.
3) There is probably no need to add new cities to the database, but you could since it's CSV based. Remember, every city in the world that has 1000 or more habitants is included in the database.