the 3 that you mentions being pullets are "chest bumping" do hens do this? I thought it was a roo thing... I am new to chickens (1 year) so I definitely could be wrong!! Here are 2 more pictures of chick one (which i thought was a roo...)
Pullets will chest bump, flare hackles and play fight as much as cockerels when they are setting the pecking order. I'm still not sure about chick # 1.