RPG Tutorial

So I was brainstorming and trying to think of what systems I would need to create in order to have a fully fleshed out RPG. I came up with this list that would need to be created:

Game State Manager
Story/Quest System
Character controller
Inventory System
Item system
combat system
UI/HUD System
Class System and Progression
Character builder
Simple AI system(for generic mobs)
Advanced AI System(for boss/special NPCs)
Stat System
Multiplayer/Networking System
Save/Loading system
Chat system

My first question is, did I leave anything off that an experienced developer would add to this list?

I’ve found tutorials for some of these things, do you know any good/great resources for these things?

The one topic I can’t find any information on is how to take these individual systems and tie them together to get a complete game, if someone has information or tuts on this it would be a huge help.