Default [Q] Hi, I just changed my phone to note3, and I want to root my phone.

Hi. As I said in the title, I've just changed my phone to samsung galaxy note3, but I'm not sure how to root this phone cuz I used to use a galaxy s2 before I changed my phone. ps. I live in South Korea and I'm using a Korean galaxy note3 ( sm-n900s)
The things I want to ask you guys are these
1. How do I root this?
2. Is there any custom roms that can be installed on the note3 jellybean 4.3?
3. When I root this device, does something happens to the knox warranty thing? When I searched a Korean developer forum, they said if I root this device, the knox warranty will be broken so you'll not be able to get free a/s.
4. Is the way of installing roms on note3 same as the way of galaxy s2?
5. Is it ok to install non-korean roms on my note3?