Guitar Question If I 'unfloat' my Ibanez edge zero tremelo can I use alternate tunings without a full re-setup?

You need a device called a tremol-no. Im not sure if it works with that tremolo, but it works with most others. Otherwise you would need to block the tremolo and add extra springs so the tremolo always returns to the beginning position but no matter how you tune it, the springs will always have more than enough tension to keep the bridge on the block. Ibanez made a part, I think it was called the backstop which consisted of a L bracked and 2 small screws to block off your tremolo in exactly this way.