To adequately answer all of your questions would require writing a small book.
Since Randy Horton has already written an excellent book that has all of that info (and more), and since his book is available absolutely FREE, I highly recommend that you download it to refer to whenever you have a question.
The book is titled "Understanding Your X-Terra", and you can DL it here.
http://www.minelab.com/__files/f/258668/Understanding your X-TERRA A4 size.pdf