New dungeons and mob stats

Just some minor questions about the above mentioned topics. Where do you get the exact files for exact monster spawns, quests etc? Are these things also stored in the client or are these these new deungeons made by observation from the official server?

Last are the mob stats which I think you can only get from server files. Are there ways to maybe get these files or is everything new custom made?

MissionDungeon.scp for dungeon mostly. Nmap.scp is for world mobs. If u want to add new mobs/maps/dungeons from official u can easly open their enc files and then read all lines there is, anyway that is just client side part so all about server side part u have to add/edit on your own.