Are you 100% sure about that point 3? Police are VERY good at intimidating people and insisting they have a right to do something they clearly don't have the right to do. I'm guessing the average bank employee doesn't know about the forth and fifth amendment...or care. It's not their paperwork. That being said, the bank can't open the box without your key. They need to drill it out. I presume that's something that will definitely put the brakes on the demands of the police. By that time, perhaps a bank lawyer will be involved.
bamks are pretty good at knowing and following the law as it pertains to their business. I don't even think a bank could let them into your SD box w/o drilling your side of the box , i wonder how big a process that is? I suspect it would involve a lock smith and an officer of the bank being on hand