It would be one thing to address the criticisms, defense in hand, and suss (to use the amazing British colloquialism) them properly. Instead, we're left with a bunch of loose ends, perhaps better termed a categorization of the critiques instead of an attempt to answer them. This brings to mind the question, "What is Plato shooting at, here?" Is he categorically listing these problems in hopes that a student will, at some point in time, come along and solve them properly? Has he finally reached a point where he's feeling backed into a corner and is, in some small way, acquiescing defeat? Or is there some other game going on, unknown to this lonely undergraduate?
If I were to place a wager, I'd say that Plato was laying out the problem in hopes that some future student could work through them. This guess does have some implicit issues, however, since Plato claimed knowledge of the Forms and that such knowledge was only the result of years of undertaking and actively working through, it's dubitable that Plato had the confidence in, essentially, anyone to reach this point. Without understanding the Forms, how could one be expected to defend them? (Which brings up the side point of the convenience in stating that the special knowledge of the Forms makes the knower sound crazy, a nice fallback point to those accused of insanity.)
Plato's greatest student, Aristotle, did indeed pick up the forms, but instead of relying on reason alone, Aristotle opens the door for empiricist understandings. Thus, while certain friends refer to themselves as Plato's Footnote, I'd be more comfortable as Aristotle's Footnote.