Sellers always have the right to say no. If you don't feel comfortable giving money back to the buyer for sellers' assist you may not be able to make an offer work. Since most people have to go FHA these days they need to have at least 3.5 % down, 1.75% up front lending fee, plus the rest of the closing. Then it is also required to have money in the bank after closing to ensure they have their mortgage payment. In this market buyers are looking for sellers that will work with them. Usually you can find a solution that will work for everyone, but it you can't then the buyer may not be able to buy and that means the seller will have to put their home back on the market and wait for the next one to come along. Most of the time if you speak to the mortgage company you can figure out a way to get it on the HUD. If the buyer is already at the max for a seller's assist the buyer and seller will then need to decide how badly they want the deal to work. The mortgage companies are changing things everyday. There are more rules coming from the feds. We all just have to change with it. Mortgage that were approved 2 years ago may not be able to approved today.
I haven't heard of anyone being asked to reimburse money unless it is owed to them for things that have been paid up front.