New mouse sensitivity and native DPI ?

[Kaliden]

I recently purchased a "razer deathadder elite" with 16000 maxinum DPI and 125 to 1000 Hz polling rate. I am now looking at having a new sensitivity for FPS games such as CS:GO and Rust which are the two I mainly play (both at 1920x1080 if that helps).

I am looking to get an end result of 20 to 30 cm/360 in-game.

I know that things that contribute to this are the In-game sensitivity, windows mouse settings(6/11 and acceleration off), mouse polling rate, and mouse DPI.

Here are my 2 questions;

>I know I must set my mouse's DPI to what I feel comfortable with, but does that have to be a multiple of 800 to be more accurate? or does it have to be a multiple of the deathadder elite's native DPI? (if so, does anyone know what it's native DPI is?).

>Should I set my polling rate to the maximum 1000Hz? and how come.