Can dislocated elbows cure naturally?

Not usually? The short answer is no -- unless you were born with them dislocated, and are having no problems -- then no treatment would be necessary. However if, it isnt such a situation, then it is extremely unlikely that it will improve on its own.
No. No. Not unless they are reduced back into proper alignment. Also, the longer they are left dislocated the more it may take to put them back into place.