Nesposito if you feel that nobody is looking out for you then there is a serious problem with your representation. Call up your broker, NOT your sales agent, and explain to the broker that you want to come in for a meeting. Tell the broker what is happening, and that you want to sit down, IN PERSON with the broker, and have the broker explain ALL of the terms of the sales contract. There is not really such as thing as your closing documents. The purchase contract and associated disclosures are part of the documentation for the real estate transaction. The other pertinent documents are your loan documents which is really between you and the lender. Your purchase contract needs to be fully explained to you if you do not understand it all.
If after the conversation with the broker you still feel uncomfortable then yes call an attorney. I do agree with sdr that real estate attorneys usually are not simply to explain the purchase agreement. I would also presume that your agent used the standard CAR forms with possibly the short sale addendums and possibly the San Diego County addendum to the purchase agreement. All these are very standard and no matter what the seller or the sellers lender has said, those documents bind both parties and so do the dates that are on those docs.
So… take a breath, call the broker, go to the office, sit down and have him review EVERYTHING. Then see how you feel.