So on the rare occassions that I get to mind control in instances with my Shadow Priest, I spend the first few seconds disoriented and fumbling to click my otherwise unused pet-bar. I was thinking about setting up one of my other flippable hotbars with macros like this:

So that as soon as I Mind Control a mob, I can press shift-down and get the mind control bar. I could also use this bar for the Shartuul Transporter event I suppose.

1) are these macros correct? Any suggestions for these kind of macros?
2) Is there a mod that will detect when I have the Mind Control buff and flip my hotbar for me?

You used to be able to do that with discord bars back in old school wow. I don't believe you can do it anymore though.

I have a set of shaartuul macros on a seperate bar that work fine; they're on a different machine so I can't verify that yours will work, but it looks right.

Those should work, if your normal action buttons still have some space left over, you can even take it one step further. For example:

/cast [nopet] Sinister Strike
/petattack [pet]
/click [pet] PetActionButton1

This way you don't even need the action bars to switch to allow you to simply use your standard keybinds. The only downside I can think of is that the icons won't match up, but that shouldn't be much of an issue.