If you have increased expenses now, with your father in law & are asking about whether you would qualify for a HAFA short sale, why are you asking about buying another home for $450K brand new?
If you do a HAFA short sale, you will not be able to buy another new home.
If you're money is tight with the medical expenses, you will not qualify for another home right now because your debt ratios are going to be too high.
How are you going to close on this short sale that you've been in process with for 90 days? Do you have a co-borrower? If so, that's great, but if you start attempting a short sale on another one of your existing residences NOW you won't be able to close on this other purchase.
Going over & talking to the seller of this short sale is not going to do you any good. The seller is not the problem, it's a cross between or either of these two things that is causing your delay 1. The listing agent being inexperienced with short sales or 2. the sellers' lien holder is taking their sweet time with approving the short sale, which is not uncommon. Fast & Short Sale are 2 words that are not synonymous (with very few exceptions)
You don't need to order an appraisal yet until you have short sale approval. However, there's no reason why the seller can't prepare & give to you the required California disclosures, at the very least a Transfer Disclosure Stmt or Seller Property Questionnaire, just ask the listing agent to get the seller to do that now.
Please let me know if I can help you any further, I have LOT of experience with short sales.
Realtor Since 1996
Main Street Realtors
Short Sale Expert