Does adding oil and fats affect bread crust development?
Oil definitely changes the crust, and whether or not it's "better" depends on what you're going for. Oil in the dough tends to give a softer and thicker crust, while a lean dough tends to give a crisper and thinner crust. Other dough ingredients that tenderize include milk and eggs, and there are plenty of web pages listing "dough enhancers" that give various effects. Again, it all depends on what type of crust and crumb you want.