Is it possible to...

…make major story characters (Alyx, Eli, Kleiner, Gman, etc) follow you around as if they were citizens? I ask this because the stuff i do and make, i need someone who wont die the first time they get bitch slapped by a zombie, or raped by an antlion. So, if you can, can anyone make it?

Edit:

Oh, can it be made that NPC’s drive cars?

can’t you just use the model swapper?

Whats that? (linky?)