Just to make sure on Any other version than 1.4.0 it will brick, but on 1.4.0 Nintendo forgot to re enable the RSA verification of the whitelist so we can flash a crafted one.
First bumping posts is not allowed here, second if i'm not going to help you that is my own business and you've got nothing to say about that. I would recommend you to follow this guide https://dsiguide.me/ it is more clear for someone who doesn't know all the acronyms.
Yes you will need to hack your 3ds that is now possible on the 3ds on 11.6 with seedminer.
edit: http://gbatemp.net/threads/seedminer-single-system-dsiware-injection.495685/
yes and if you are done editing open the command line in the folder with the project and type make that will make the .nds file, make clean will delete all building residues (.o .a files) and delete the .nds file.