You need to use those diff and changed the extension "System/itemInfo.lub" into "System/itemInfo.lua" if you update kRO often, as they will get replaced when you update kRO. You must have itemInfo.lua in system folder, either the translated or your's modified one.
The other question depends on your setup, how many grf file that you use, are your custom items ID have conflict with the original rA items. Mostly you're on your own on to fix this issue.