Suggestions to create custom fixtures?

Premise: I use FM Editor terms, so you have to know it or can be hardly understandable.
I'm going to create real Italian Serie A fixtures, but I would like to know some things:
Is it important to set matches in Opening and Closing Stage Fixtures tab, or I can set only matches in the Fixtures tab?
Should I set Date Index, Date and Time of matches or is better to leave it blank so the game can decide based on Cup matches?
How work the Home Goals and Away Goals tabs? It works only if you don't play in that league?

I've completed the file, but it doesn't work. Game disable Serie A when I enable the file.