Please read my answer inside:

What the agent said is pretty much right.
1. All short sale is As-Is. You can put any thing in the P&S agreement but accepet or not depending on the seller respond.

2.If the bank belive the buyer have no promble for finace, they may not care if you put cash offer or not. But as I know right now the financial situation, I still belive lender love cash offer. But it is hard say to every individual lender. If they don't care just don't care. I was not them, I can't say they do care:-).