Quirk Questions (I need answers)

Biology

Given how Setsuna can still feel through her detached parts, and also seemingly have blood running through them, does that mean instead of detaching her limbs and moving them around, it's more accurate to say she's controlling portals she can form around her body?

Does that mean she can eat food by just floating her hands and head to the table to eat?

If Tetsutetsu Tetsutetsu's skin is made of iron, does that mean he can rust?

Can you melt Kirishimas skin?

Would it turn to magma, or burned flesh?

How does Fatgum's organs survive the pressure surrounding them from the fat?

If he's always walking around like that, does that mean his muscles are also quite strong to be able to lift all of that?

If Momo creates straight fat, does it make more, less, or the same amount of fat consumed?

How does Bakugos hands spark? Does it just create them from thin air, or do his cells act like flint and steel?

If his sweat glands are filled with something like nitroglycerin, how does it not react when he creates explosions right on his palms?

If Izuku cries so hard to crack the concrete he's standing on, then how much water does he need to consume?

Is Eri's horn connected to her skull?

Do animalistic mutation types go to a vet or a doctor?

If a transformation type transforms into something with completely different biology, where do the unused organs go? Like when turning into a fish, do the lungs just meld into the skin? How does it come back when they transform back then?

Going down that thought, does that mean that every time they transform into something with no organs like a jellyfish, then transform back, will their organs stay the same as before, or be recreated in perfect health?

How do wounds transfer across transformations? Especially with those with inherently different biologies, how would the injuries stay consistent?