The answer will depend on the language in your purchase and sale agreement. Specific performance, is a remedy that will force them to do what they agreed to do. Rescission would be you get your earnest money back. Which you remendy could sue for will depend on the agreement.
You would be well served to see a eal estate lawyer in Seattle and find out what your remedies are as the buyer.
Yes, depending on the terms of the contract you signed governing the purchase transaction. However, you might try to contact the escrow company to see if Fannie Mae will agree to close the transaction and keep the amount of the claimed condo fees in escrow pending resolution.