What to seal head studs

How would you be getting water under your valve cover, yet none in the oil?.. It must just not be enough to notice it in the pan.

Sounds like a head gasket to me though. I'm not sure what you mean by the top underside of a valve cover is. If you mean between the deck and valve cover, it sound's like you've got a valve cover gasket leak as well if it's seeping out.

It sounds like to me that your crank case ventilation isn't working properly and you've built pressure in the crank case, and now it's found places to escape. Or your valve cover bolts are improperly torqued.