I think it's a good idea but I wouldn't want to have things like that said without me beeing there and telling this some random guy^^
I think it's a good idea to have offline players work as NPC, since often you dont know when he will be back, maybe you miss your mate several times and wont be able to even create a barrel because he doesnt know you could need some metalbands.
But there are several problems I personal wouldnt like about this.
first of all, I wouldnt want my charakter to tell someone I dont know things about my leader or give him that much information about the area (would I be able to disable this feature?)
So maybe you can just write some lines the people will read if they want to talk to your NPC-self.
Also having your NPC moving around would need a good working pathfinding algorithm, sounds not that hard but it will naturaly cause a lot of problems if you just get stuck somewhere or run across the island because it somehow failed.
(will it just be produced/cleaned etc. without my NPC moving around?)
would not give me a good feeling if I log in and get overburdened with dung or metalsheets, or will the produced things move to a warehouse?
and where do I get my resources from?
So while the idea itself is very good (especially the part with being there and the chance to be killed while being offline)
it will cause some problems if we dont think about it enought.
The only thing I realy dont like is, why would I want to change a game, where the fun comes from the time you need to spent to accomplish something, into something I could play on my smartphone?
(but befor anyone will tell me he wants to play even if he doesnt have much time...well, ok with me but everyone who wants to play should do it himself and not change this game into some boring browsergame, there are plenty already)