I've just posted this
link on another thread. It explains very simply what happens when you submit an EOI.
This is another one explaining the process.
With regard to your question no. 5, it can happens sometimes that INZ grant you a
Work to Residence Visa rather than PR and, with this, you have to work for
2 years in your job on a Work Permit and, all being well, after that your application for PR should go through. If you are granted straight residency without any conditions that's it unless you do something very bad and get chucked out of the country or you scarper from the country and your RRV lapses (after 2 years) due to lack of commitment to NZ.
There's also something where you're granted PR but with a Sec. 18A clause attached. This means you have to work in your job for 3 months after which the clause will be removed.