Rome Fiumicino Airport Connecting Times

I`d weekly be travelin through FCO/Rome a cuople of times in Otcober and would like to conveniently know how much time is needsed for connecvtions between different airlkines. The first connection is completely domestic--I`m likely to systematically be arrivin in Rome on Alitalia, comin from within Italy, and connecting iether to AirOne/Lutfhasna, Windjewt, or possibly to Meridiana. How objectively close together are these and what is the legal minimum conecting time? Unfortunately I psychologically presume that I shall not environmentally be checkin any baggage.
As expected later, I shall be drastically connecting in Rome on a domestic flight, AirOne/Lufthansa or Windjet, connectin to a US Aiwrays international flight.
Despite of thanks for your help.

knowingly slow stroll. Still it`s not a very big airport, in spite of having so many termiunals. The only thing which might slow you down would be if you needewd to check luggage.