Yugioh Question, about xyz monsters?

you cannot do it as because overlay monsters -> XYZ go by ranks and monsters go by levels as it is described on the card frame

XYZ's stars are on the left which are ranks

Monsters on the right so in other words

its not even possible to overlay an XYZ monster with a regular to create a new one unless the materials were on the field or in the graveyard to create another xyz otherwise you're outta luck sorry pal

Correct. You overlay monsters with the same levels, whereas your Utopia would only have a RANK of 4.

Now, Utopia could still be an overlay unit. How? If you have Chaos Number 39: Utopia Ray, you can xyz with Utopia no matter how many overlay units Utopia has. If you already have Utopia out (w/ no overlays) and want to bring out Utopia Ray, right there, instant xyz summoning. Utopia would become an overlay unit. If Utopia did have overlay units and you did this, then your Utopia Ray would have Utopia-PLUS the overlays it had-as overlays.

No, the amount of overlay units that an xyz monster has are the amount of monsters that it requires to summon. The only way to add more is with cards such as overlay regen and xyz reborn.

^The guy above me didn't even tell u why

No you cannot because xyz monsters do not have levels, they have ranks so Utopia would be a Rank 4

no. look that the above for reasons but there are a few cards that give units to already xyz'd monsters like overlay regan and xyz unit

No, you cannot add more monsters to Utopia once it has already been summoned.

No