The title pretty much says it all. 

HumanNPC has a built - in message system that NPCs use when you talk, approach, leave etc.

But these are single messages that don't require or accept further player input. 

Rust already implemented this. Like when you talk to Air Wolf or the new mission givers. I'd love to see a similar system and would probably invest a buck or two in its development.

The intent is to interconnect lore, quests and backend switch flipping/variable setting in a friendly ui that displays messages and expects (or not) a player input to continue and eventually run commands, call hooks and whatnot.

Think of this as THE plugin for PVE servers that want to engross players with storytelling and choice/consequence scenarios.

I have no knowledge of cs. I read code, I modify it matching the Syntax and that's as far as I can do anything in that direction. But I have a good vision for developing software and am very pragmatic in testing and finding a good functionality vs overhead compromise as I've been dabbling in game development for over 10 years now. I am more than willing to take an active part in this, provided that someone with the coding skills comes in. 

Google talking npc vendors

exactly! thank you! I didn't know this existed