Hi Bamboo and welcome to the forum. Though i live in Cincinnati these days i was born in Brooklyn, so i guess we are homeys bro!
That's a pretty big order of question there. My best suggestion would be for you to spend an aweful long time researching the archives since everything you have asked about has been discussed in depth here for many years. You should research the old site as well as this one. There are some VERY good threads on restoration and care of keris and i would hate to have to start new ones up again when the info is already in the archives. If you then have more specific questions ask away.
Just a word of advice, we are all students here, all at various levels, but students still. The sad truth is that there are very, very, VERY few people around that understand the full picture about keris, even in Indonesia. So if i were you i would take everything you hear with just a little grain of salt and beware of those who might set themselves up as experts.
I would also suggest that along with studying the keris itself you also study the cultures of Indonesia as well. It is impossible to come to true understanding of anything in a vacuum.