You can counter what the bank has sent to you but it is highly unlikely that they will change anything. As you probably noticed, the bank's addendum probably has everything in their favor and nothing favoring the buyer.
It is very frustrating that the banks all have their own addendum and it changes most everything that the CAR has in their contracts. The California Association of Realtors has spent a lot of money perfecting the contracts but yet, the banks hire more attorneys to turn those CAR contracts upside down.
Be prepared to walk away because they most likely will not see things your way. I will say that I have sold REO property and the buyers have accepted the addendum and didn't have problems. That is a choice you will have to make.
Sorry - wish I had better news!
The Chance Team
Keller Williams Realty
If you can't live with what they're looking for, move on. If you can live with it, still be careful with the deadlines. Despite the advice from the banks' listing agents, I am successfully getting approvals and ratifications using an addendum I created which protects my buyers. Check it out. Good luck. (You do have an agent, right?)