The best advice i can give is that Google is your best friend on that matter. I have changed a LOT of the base code and structure, as you will be able.

I saw some potential to improve it whilst learning along the way. The base game mode was written by Lystic. But i will not say more because even i don't know what i'm talking about. 'Battle Royale CQC' was developed by me from 'Battle Royale Ghost Hotel' as a learning experience to do with scripting/coding the Arma 3 engine. If i look at our setup we have a steam account for our server (so we did buy another copy of Arma 3 to do this) and its from there it runs. pbo's to the server, HC etc) so i know very little on the setup. Personally i never did a full setup of a dedicated, i only do the admin stuff (loading missions, adding.

All the instructions on how to setup a server is here. The simple answer would be from bohemia's wiki Here.

If i understand your question correcly you have a 'root server'? Is this just a machine where you host files in your home? If you have a good connection and the machine has at least 4gb of ram and a good CPU (i5/i7) then you can host on that machine. Well it depends what kind of server you want, the easy method is a local host where you host the game via the server browser but it can be laggy or cannot be accessed by other players because of firewall etc.

How to play arma 3 battle royale