I'm glad that your head is still intact from my babbling.
What I was talking about is not "official" sacrifices to someone specific (ie Morgoth), but rather murder that is ordered by the king that make Morgoth's dream (chaos etc) come true.
The Valar rarely interfere with the outside world. Not because they don't care. Because they leave a choice to the Eruhini. They sent the istari - you might think "big deal, 5 old wizards!" but it's more than that. It's a way to
assist ME without
completely controlling it.
Sauron came to Numenor because Pharazon took him there.
At the end of the 1st age, Sauron was left alive because of pity, as I said before. Later on, the Valar did not interfere in the world's affairs for a long time.
I'm trying to say something more complicated than my brains can hold. I'm confusing myself, and probably going in circles with my arguments. Gonna go hang my brain on a clothsline for a while to air out.