You can always ask, but understand as other respondents have said. The seller has no money to make repairs. The bank is already losing alot of money in accepting less than what is owed, and you risk a delay, if nothing more, if the bank goes back to their investor for approval. Short sales take a very long time in most instances. Your request may require that they go back and start over on an approval.
If it's worth it, I'd consider just taking it as is despite it not being in the exact same condition. And if it's that bad, you may want to walk away from the transaction. Waiting for the bank to approve a credit for repairs, may put the approval back in never never land. - Earlier today