IMHO
Free ranging successfully depends on the birds themselves and the breed. While a 'flighty' breed may be better, other breeds free range and stay mostly safe if they are used to it. Especially when they lose one to a predator, they become VERY wary.
I have jersey giants and naked necks, calm friendly birds and free range great.
As far as too friendly to humans not good , I don't think so unless they're silkies.
I don't like 'friendly' birds, annoying. I don't have them for pets, I want them to do their thing and I do mine. I've had silkies, annoying, peck your toes when you feed them, won't move out of the way. I didn't think the naked necks would be the same but the girls are annoying as heck, crowd you right around your feet, push them back away and they are like magnets. The roosters don't but the hens do. The giant's don't, a very calm non-flighty breed but not overly 'huggy'.
Not biting the hand that feeds them, I don't think it affects their ability to stay alive in a free range setting with predators at all.
I've lost very few birds over the yrs and I'm surrounded by various predators.
(I do pray a lot though

)
Edit, forgot to add, they will scratch through and eat anything they want to by the way lol
