I understand the apprehension of GMs allowing any starting character the ability to grab gear that was designed for advanced DW marines to use. Give the players an inch and they will take a mile.
I also understand that in the fluff (which with GW tends to change) for any marine to be selected for DW they have to have proven themselves on the battlefield already. Hence the 1,000 points you are given at character creation to reflect this.
I would say that as a "giving GM" it wouldn't be broken or to crazy to allow all players a 1d5 Renown at starting character generation. The only requirement would be that the starting Renown could not exceed your Fellowship bonus.