When the grease starts to fly its time for a new one. The boot doesn't matter. Yes it will make it wear quicker but it's two different spots.
I started seeing grease slinging on mine and within a week it started to click. Being that it's the front you will be fine for now but be prepared for it to fail if you don't replace it. You need adjustable LCA's with the aftermarket shaft to set the pinion angle.