You have two separate (probably) problems. First, the pedal going to the floor undoubtably means that for some reason, you still have air in the hydraulic system that wasn't bled out. You did reinstall the spare caliper with the bleeder screws uppermost, right? With bleeder screws pointed downward, it will be all but impossible to eliminate air from the system. The vacuum booster will have no influence on a hydraulic problem.
A non-working vacuum booster simply makes the brakes harder to use but they'll still work. Some air is displaced from the big cylinder as engine vacuum assists the pedal travel each time one steps on the brake pedal.
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