Roster Control Help!

[bad8]

Can someone explain this to me please. I just got the game and need a little help with my franchise. I started a franchise with the braves and advanced to the regular season. My line-ups were screwed up. Ok, so I fixed them. 1st game against the Cubs had Derek Lee hitting 2nd and their line-up so far off. What is the deal with that? Is there a way to fix it? Also I see in threads people talking about controlling all 30 teams. What is that? Does that mean trades and injuries are off? Making me control every team and having to replace tired players for teams I am not using? Is there a way to play the game with correct rosters and injuries on? Thanks sorry Im a noob but I love the game I just don't understand everything yet.