I would think that you could add an addendum that the seller will not market the property or accept other offers while waiting for approval. That would not solve your problem though as it is unlikely that the short sale is going to close as quickly as the sale of you home. I've been waiting for 2 months and have no idea how long this will take. If you want to accept the offer on your home then you'll need to find a place to live while waiting for the short sale.
So while you are wandering about aimlessly looking for a solution to your problem, there is some secondary lienholder in another state refusing to sign off their lien. And that is an insurmountable obstacle to closing.
Your Realtor could fill you in on that. Buying a short sale (or a foreclosure) comes with a level of uncertainty unmatched in any other real estate transaction.
Carefully read the documents you do have, you may be surprised to find how little ground you have to stand on.
"Locking in" the purchase of the short sale is unlikely at best.
Homeless is a solid possibility.
Best of luck!
If they do not approve of the sale you have no ground to stand on and your offer could be displaced.
ALWAYS CONSIDER HIRING AN ATTORNEY to help you navigate and understand where you stand and all the possible legal scenarios that may arise. Short sales can be a GREAT WAY to purchase a property and receive a great deal! With greater risk can come greater reward. Your patience (and your agent's) can be greatly tested in a short sale... Be prepared for that.
Shawn Kriewaldt, Broker Associate
Keller Williams Realty - West Madison