Sorry for me being very blunt now but:
Its VERY HARD work to createt a balanced multiplayer game when the players can choose different weapons to start with.
You need to create an extremly clever map, edit every single gunspec - and still the guys with the smg will win 90% of the time.
If you want to create a halfway enjoyable multiplayer game, then simply give everyone a pistol and let every other weapon spawn on the map.
PS: If you like CoD just stick to playing it. You will never recreate anything even near to it with FPSC.
In case you find my grammar and spelling weird ---> native German speaker ^^