flavored vodka pie crust

I would stick with straight vodka for pie crust, but you could press finely grated lemon zest into the crust.

What you're contemplating may work but it's not the most efficient (i.e. economical) method of adding flavor. A few drops of essential oil or some extract will accomplish the same thing and you could be certain of what went into your crust (flavored spirits don't always use natural ingredients). On the other hand, you could substitute rum or other dark distillate for the vodka.

Note: Reducing the vodka over a burner would defeat its purpose; there would be little alcohol left after doing so.

I haven't tried this, but in my experience, booze and its flavor evaporates when baked. I don't think you'd be able to taste the flavor much. If you want to taste the flavor, you could try reducing the flavored vodka in a saucepan first to make it thicker and stronger, then chill it and add it to the crust.