Your realtor would have set expectations about short sales: there's nothing short about it except tempers.
And yes, it can and will take time to process. Furthermore, there are no guarantees that a short sale will even be approved.
Although the BPOs may have been ordered, that's not the end of it. Some lenders will or may require more than one BPO. And if there is more than one lender, that complicates the short sale.
And no... you cannot contact the lender or the seller or the seller's agent. Work through your realtor (and hopefully your realtor is also experienced and knowledgeable about short sales). Unless the seller has authorized you to speak to their lenders, there is no way on earth you can get past the first phone call. Besides, you will only serve to muddy the waters. Leave it to the listing agent and the seller to negotiate the short sale with the lenders.
As an experienced short sale realtor, I can boldly say you have no idea what it takes to negotiate a short sale --- regardless of how many times a listing agent calls, faxes, follows up, etc.....a short sale will take time.
Since there are no guarantees to a short sale, and if you cannot wait, then go ahead an look for other properties, and stay away from short sales. You will run into the same situation over and over again.
To get a sense of the challenges we encounter with short sales, visit this forum and you'll see for yourself.