I've attempted to lower the action on a Squier Stagemaster 7. The action is fine at the nut but is very high toward the bridge end, I am unable to screw the posts in anymore. What can I do to gain more adjustment at the bridge end/lower the action.

I was thinking I could punch out the studs and replace with oversized studs that I will sink into the body by 2-3 mill more, I could put a shim between the neck and the body or I could machine a couple of mill from the bottom of the bridge but I am worried this may effect tone. Is it possible to get smaller saddles for Floyd Rose's?
Add another spring into the setup, that will add a shit ton more potential adjustment room but your will need to unscrew it a bit
Adding a spring won't help at all. He said the studs have bottomed out.

As far as I know you can't buy smaller saddles. Your best option would be to shim the neck. You can use card/paper, or you could make a wooden shim. The wooden shim would be harder to make, and realistically you won't be able to hear a difference (unless you're Eric Johnson )