bob
It's better to have two hands than one glove.
What exactly do you mean?...
Which word didn't you understand?
A pdf created by Illustrator is often the EXACT same file as the equivalent ai or eps.
Sure, if you're not saving a conglomerate of different objects in different formats but just a simple object or objects there is no reason for it to be any different. But that has nothing to do with the notion of 'converting' a PDF to some other format. Things are extracted from a PDF much like extracting a book from a library. Once extracted, then and only then can they be translated into other formats.