^ Yep. Less that .035" quench seems to hurt performance (upper power band) in my experience. That's why I settled on that.
For valves, it's as long as they don't hit. If it's a big lift cam, you had better not be kissing the head. We routinely valve pocket the heads for big lift cams so that they do not hit. Actual clearance above the valve doesn't seem to matter, as long as it doesn't hit. Another thing to consider is if you have any valve float at all and how heat affects the clearance. Better to be safe than sorry.