Parity argument about freedom in hell?

I just commented on a post here regarding eternal punishment/reward for some finite sin/virtue.  For what it's worth, this is just philosophical reflection and not in any way a record of my position on heaven/hell.

Some atheists respond to free will theodicies (particularly those that claim free will is a necessary precondition for certain goods) by pointing out that, presumably, we can't sin in heaven.  So if free will is valuable why take it away in heaven?

First off, in what sense should we say one can't sin in heaven (by the way, I am putting aside issues about eschatology and catering to the common misconception that heaven is where we will spend eternity...sorry Randal!)?  Does this compare with my assertion that I can't run a mile in 2 minutes?  In that case the more general way of saying this is: given some set of prior conditions, it is true that we can't sin in heaven.

All that aside, we have neglected an important issue.  What about hell?  Can people in hell choose to be virtuous?  If not, might this help explain why C.S. Lewis thought that hell was locked from the inside?  It isn't that they are getting everlasting punishment for a finite amount of sins.  It's that they are continually sinning and being punished for it over an everlasting duration.  Sounds great, where do I sign up?

Switching back to heaven now...perhaps we can choose only good but we get to choose between things like getting 100 virgins or getting 1000 virgins.  But isn't something fishy about the possibility of choosing 100 virgins when one could choose 1000 virgins?  That is just an instance of a general problem of extrinsic goods in heaven.  (Perhaps the same reason Anselm believed there could be a greatest conceivable being but not a greatest conceivable island.)

My intuition suggests that heaven is not lacking in the goods department.  But then how do we make sense of choices in heaven?  Do the goods in heaven continue to increase without end?  That seems to be a possible defeater for my problems with choosing 100 virgins.  On a potentially infinite road trip, it doesn't matter if you stop to pee 10 times or 100 times.  You'll still arrive at the same time.

But are't there people missing from heaven..in hell...that might have contributed to some further goods in the endless long run?  And won't they be going on a potentially infinite road trip in the evil accumulating direction? And again, it doesn't matter if you have 10 in hell and 20 in heavy.  Given an endless amount of time, it seems to me that they'll net to zero.  What a catastrophe!  Luckily, I'm pretty sure I'm mistaken though I can't see where.  This is why philosophy is fun!