[Aule]

I think i might be able to answer one of the last questions.
You said that the Valar took no action during the 3rd age to help the races of ME. But they did, they sent the wizards to provide assistance to Men and Elves. But they were sent back in a deliberately weakend form so that they would have to find other ways to help in the fight against Sauron other the brute force.
The Valar had bad experiances when dealing with men in the past. ie When the numenorians began to rebel and eventually did. The Numenorian didn't pay attention to Manwes Herald (i forget his name) when he came to talk to them and council them on the reasons why they were not allowed to enture to Erresea (spelling?).
The Valar found that direct intervention in the lives of men only led to misunderstanding and further trouble. That is why the Istari were sent in a form of lessend power and majesty.

I have sometimes wondered why the Valar never took a more active interest in the lives of Men when the first awoke. If they had done so then, men would not have come under the influence of Melkor and would therefore not fear death (as it was Melkor that first put the idea into there minds that death was to be feared), without this fear of death Numenor would never have rebeled.
I'm not good at getting my ideas across but i hope i have been of some help in answering a few of your questions