Assuming this is true (and it's plausible), getting top secret clearance is _not_ going to be the same as getting unrestricted copies of every large government database. It presumably just means you have permission to read _some_ top secret documents, on a need to know basis?
Yes. There's still a process to access classified documents, and they will try to give you as little access as you need for your task when granted. You need to be very specific about what info you need (more broad access makes it easier to deny).
I'm not even entirely certain the president can just walk in and grab treasury access that easily (but the president always played by different rules. He may indeed be fast tracked).
