Is it O.K to substitute reflexives for PRO
No. They are different. Even if both are possible, they would have (at least subtly) different meanings.
I wanted myself to go home
This sounds very awkward and indirect to me. I'm not sure it's acceptable (it's so weird-- why would you say it this way?), it would have a meaning like:
I wanted her to go home.
I wanted John to go home.
In other words: I wanted it to be the case that some person (myself) went home. It does not have the same immediate psychological sense of wanting to go home. Instead, it's a desired set of independent events.
So it's more like something you might find in a confusing fantasy or science fiction novel, where someone is not really in control of their own actions. Still, it's very odd.
*Mary hoped herself [to kiss John]
Definitely ungrammatical. If possible, it would need to be this form:
??*Mary hoped for herself [to kiss John]
?Mary hoped for someone else to kiss John.
But here, "hope" strongly prefers a "that" structure.
Regardless, to the degree that this would be acceptable, it would be the same as the example above.
However, this is very important: PRO does not need "for", but an overt NP does. Therefore, PRO and a reflexive are not equivalent.