I can't help you with the first one as Mullen19 suggested, you can add leagues to your game.
The second I can help you with. I had to try and remember the path but I just found out the path. Basically SI don't have the license for the German national side so they included a "fake" Germany. If you want to remove this, do the following.
Go to
C:/Program Files/Steam/steamapps/common/football manager 2012/data/db/1220/Inc
You will then find a folder named "all" now you can have a look inside but theres a file in the called fake. Basically this is the reason you can't see the proper players which is why sometimes its easy to sign Gotze if you offer Dortmund £100m for his first international goal or something because he will never get a call up.
If you want the proper national team, just delete the "all" folder inside Inc. You will have to start a new game for changes to take place.
And remember to choose the right database when starting a new game. 1220 is the latest database update that you will see inside the db folder. So when a new one is released, follow the same steps above but just choose the appropriate db.
Hope this helps!