Patina vs Blue vs Acid Wash?

[StormFalcon32]

My understanding of a rust blue is that it causes the steel to form a layer of Fe2O4 oxide (a thin layer of magnetite) which is more stable than Fe2O3, prevents Fe2O3 from forming, and gives the blade a dark color. I think the forced patina and acid wash do something else which is similar, and the acid wash is just a more severe/faster version. However I don't really know what the patina is doing past that. The second question is about the differences between all these processes (rust blue, forced patina, and acid wash), what causes different shades of grey, which is more of a surface level and which penetrates the metal more, is a darker color better for rust prevention, does the magnetite from a rust blue work better than whatever a patina forms, etc.
Thanks!