There ya go, a small tutorial.
Yep, use the gateway files(you don't need the flash cart) to backup your sysnand, just in case you ever fuck up your 3DS, and to make a emunand. Then get browserhax to install Themehax, install RXtools, and replace Themehax with the RXtools autoboot, then you'll have a cold booting RXtools to get into emunand.
The video explains it.
I got it working!You don't need a flash cart. You just need to go to the Gateway download site, download the correct files, place Launcher file on your SD card's root. and go to this website on your 3DS web browser. http://go.gateway-3ds.com/
Yes, with Themehax, you can cold boot rxTools.
Ah I see here's a another question do some games needs to be on a higher FW to run?Never used friends list.