Nothing wrong with flying, easier to get away from a predator

Of course in my flock, most of the chickens will clamp their wings to their sides and run rather than fly if they want to get somewhere fast. That doesn't make a lot of sense for the lighter bodied birds that can fly well. I've noticed the Exchequers can fly and land a lot more "lightly" than the bigger birds.
In my experience: somewhat. I'm not really sure what people use as the definition of "flighty".
- Is that a bird that won't come sit in their lap? That is every bird I've had except Echo, she would if there was food to be had
- One that doesn't want to be touched? That is ALL of the birds I've had, though some tolerate it a LITTLE
- One that won't eat from your hand? I have several of those, different breeds.
- One that runs for the hills if someone comes around them? I've never had any of those.
Then there is "flyer". As I said mine generally don't fly though the Cubalays would on occasion. That doesn't mean some won't fly a fence. Of the current birds, some of the 2017's will. Both Exchequers, the Barnevelder and Cassie (EE). The gate is 5' tall and they have to start from a bit down hill. They have no problem flying to the top of the fence then going over. Even my big BA can fly straight up to the 4' roosts if she doesn't want to walk the ramp from the 2' high roost.
Penelope got special treatment because she was chased from the general BOSS or Scratch area. I started holding some back walking away and dropping it behind my back when she was near so no other birds saw it.
More space is always good but I don't think the flock dynamics will change. Seems like those at the top do want to remind the others of their position in life at least every now and then.
Because chickens are STOOPID! It wouldn't matter if there was a pound of BOSS or scratch in front of my girls, if a small amount was then thrown in another area they would ALL run over to that. Your best bet is to scatter it widely.
If they can get over the fence, they might. Depends on if there is something more interesting than whatever they have at home.
Unless you want to be able to get out the door in a few days