As for the "whatever reasons" I previously mentioned, what I am talking of relates to shamanism, and the various rites of ordeal and sacrifice that were used by many cultures to gain insight into and communication with the primal spirits of, well, pretty much everything, somewhat akin to the landvættir. Alternatively, there is also the paradigm of power through discipline. If one can master themselves enough to give up something held dear, then one has gained power over themselves and is more able to focus themselves and their energies (physical, mental, whatever) on other things.
On to the second question, do the Norse Gods exist for us, or do we exist for them, or both? This question is rather close to the penultimate question of "What are the gods, and where did they come from?" My thinking would be that 'both' is the closest of the answers. I have two nearly parallel, but somewhat contradictory, lines of thought on the matter.
The first line of thought is what I'll term the "mythological " view. In this, the gods are pretty much as described in the Eddas, beings rather similar in appearance and thinking to mankind. One could argue that these similarities are due to Oðinn and his brothers gifting humanity with the mental "spark of life" that enabled humanity to move beyond living a life in the short term, and to begin having and using insight into the way the world works. In other words, to stop merely reacting to the things around them, and be able to analyze these things and see the patterns of the world and plan ahead. And of course, the gods we know and love are not the only beings of their "level", as illustrated by the various tribes of giants, some of whom were capable of challenging and even defeating the gods on equal footing. As for our interactions with them, the gods and ourselves are two parallel societies, if you will. Our fates are interwoven, but seperate. You could say that as the tapestry has been woven, it has gone from being being a pattern in which warp and weft (Humanity being the weft, and the higher powers the warp) were nearly equal, and equally seen by all, to one in which the weft has covered the warp, leaving the appearance of only the weft. Perhaps a poor analogy, but it's the best I could think up.
And that's about as far as I have gotten so far. Part 2 of question 2 will have to wait until I can recollect my thoughts, which tend to scatter in a thousand directions when I try and write stuff like this.
