As a buyer, I have on offer pending on a pre approved short sale home in Nevada City California. The previous buyer just walked and we are using the approval letter the Bank gave them. Approval was for $228k. I have offered $230k all cash no contingencies. Sellers accepted my offer and now its on bank's desk. Listing is now pending and listing agent told me no other offers will even be submitted to bank unless mine falls through.

Here is where things are getting tricky: Bank wants to close as quickly as possible because they want to use the previous approval letter they issued, which expires May 15th.  So listing agent therefor asked for 17 day escrow  to close before expiration of approval.  But now bank said they have standard 15 day time window  before they EVEN REVEIW my offer. I am confident it will be accepted as it is all cash no contingencies and above BPO. So 15 days to review offer plus 17 day escrow puts us right at May 15th, a little too close I feel, especially the way short sales are so unpredictable.

What are my options? Can a approval letter's expiration date some how be extended to allow escrow to close? Or is there a way I can speed up the process of having bank review my offer. They said that my offer is now in a stack of papers that will be reviewed in the order they were received. If there is serious "time is of the essence" implications for this offer to go through, is there any way to expedite the process?