That said, Your contract allows for a certain amount of time for you to do your due diligence and decide whether to buy the house. The standard time is 17 days, but that can be negotiated between buyer and seller(remember, seller is the homeowner) You also have a time to get appraisal and loan approval, approve the preliminary title report, Natural Hazard Report, Insurability of the property....etc. These are your contingency periods.
It is possible that when the bank does approve the sale, the time they want you to close escrow will be less than the time you are allowed for your due diligence. If the listing agent has handled the sale correctly, they would be moving the close of escrow date forward as needed. If not, they will need to try and extend or you will need to hurry through your inspections. Hopefully by that point you will have you loan almost fully approved. (stay current with your financials to your lender.)
Most important to you in a short sale is that you have a short sale addendum which states the time periods for inspections, etc begin upon buyer's receipt of written short sale approval letter from any and all lenders involved. This is CRUCIAL. Be sure your agent does this.
Best of luck
If you are ACCEPTING a COUNTER from the BANK, then you will have a signed CONTRACT>
If you are ACCEPTING a COUNTER from the Homeowners, then you do not have a signed Contract.
If you are not prepared to wait for the Bank, then you shouldn't be trying to do a Shortsale.
Good luck and may God bless