What happens when Chinese flagged ships dare us to shoot them?

Do you mean Chinese military vessels? Or do you mean oil tankers? Oil tankers don't require you to shoot you simply commandeer.

If China were to involve its Navy in opening the straight that's exactly what Good outcome could look like

Or it could be Really Really Bad Outcome, let's not be too flippant about this.

Out of curiousity, what's your good outcome from the Chinese sending destroyers to the gulf?

If the Chinese take on the burden of maintaining the free flow of shipping through the Gulf by stepping up as one of the key beneficiaries of said shipping that would simply be an appropriate burden sharing mechanism in my view.