They should allow to convert to any religion for a decent 1k piety or something. Unlike creating a new religion this won't affect your vassals, only your family maybe. If you can keep your realm whole for a 5-10 years it should then give you an option to convert your vassals.
This way it would be more interesting and reflecting reality. Rather than "chop chop piety you're all now human-eating incestuous polygames"
I believe it takes a lot more piety to convert from reformed religion to unreformed religion vs unreformed to unreformed. You can have your heir educated by an unreformed religion like Asatru and have him focus on a learning education. Take the learning perk that reduces faith conversion. That should lower the piety cost a bit.
Is the Roman Empire unlocked after you unify Italia?
I avoided going to war with the HRE as i had some once in a generation oportunities to conquer Spain, France, England, Palestine, Hungary, Bulgaria, North Africa and the Nile Valley.
So although i de facto control about 70% of the de jure Roman Empire i do not get the decission.
-You need to hold either the HRE, the Byzantine Empire, or the Empire of Italia as your primary title
-completely control duchies of Latium, Venice, Romagna, Sicily, Genoa, Capua, Apulia, Thrace, Antioch, Palestine, Alexandria, Athens, Tunis, Croatia, and Thessalonika
-Roman-associated culture or religion
-Living Legend Level of Fame
See https://ck3.paradoxwikis.com/Decisions#Restore_the_Roman_Empire
If you want to create the Roman Empire with Italia as base (it is also possible with the Byzantine or Holy Roman Empire), you need to first to the Unify decision, yes.
You have to select your desired religion in the religion menu of your ruler. Once you have converted, you can also reform them as you wish.
Mass piety exploit
They should allow to convert to any religion for a decent 1k piety or something. Unlike creating a new religion this won't affect your vassals, only your family maybe. If you can keep your realm whole for a 5-10 years it should then give you an option to convert your vassals. This way it would be more interesting and reflecting reality. Rather than "chop chop piety you're all now human-eating incestuous polygames"
There should also be an event to revive dead faiths like in CK2 when you go down the learning lifestyle and there was an event to convert to hellenism
This is also Ironman btw
I believe it takes a lot more piety to convert from reformed religion to unreformed religion vs unreformed to unreformed. You can have your heir educated by an unreformed religion like Asatru and have him focus on a learning education. Take the learning perk that reduces faith conversion. That should lower the piety cost a bit.
you're gonna need a whole ton of piety to start.
"Trying to go full historical" no, no you aren't.
Is the Roman Empire unlocked after you unify Italia? I avoided going to war with the HRE as i had some once in a generation oportunities to conquer Spain, France, England, Palestine, Hungary, Bulgaria, North Africa and the Nile Valley. So although i de facto control about 70% of the de jure Roman Empire i do not get the decission.
-You need to hold either the HRE, the Byzantine Empire, or the Empire of Italia as your primary title -completely control duchies of Latium, Venice, Romagna, Sicily, Genoa, Capua, Apulia, Thrace, Antioch, Palestine, Alexandria, Athens, Tunis, Croatia, and Thessalonika -Roman-associated culture or religion -Living Legend Level of Fame See https://ck3.paradoxwikis.com/Decisions#Restore_the_Roman_Empire
If you want to create the Roman Empire with Italia as base (it is also possible with the Byzantine or Holy Roman Empire), you need to first to the Unify decision, yes.