try holding them close to your chest so they can feel your heartbeat. It sometimes helps them bond to you. I learned this with cockateals years ago and it seemed to help with the chickens. I also let them hear my voice approaching before i try to handle them. I still do this when i go out to their coop/run. Now they come to see what i've got for them. Good luck and welcome to BYC
I scoop mine up with my palm against their chest and my finger between their legs and they don't much mind. It think it depends on how you pick them up if they feel secure or not. I think putting your finger between their leg makes them feel secure, mine will just dangle their legs and relax.
they may be pecking because they are too crowded. Make sure they have plenty of space. You may also give them some mashed up boiled egg to supplement their protein. They will try to eat feathers for the protein. Some pecking will be normal, just make sure they don't draw blood. Good Luck