The missing toes is common for hatchery quality Silkie chicks.
Handling your chicks will not harm them or kill them. Don't keep them away long enough to get cold and they should be fine. Keep calm and be gentile, that's about it.
As their feathers start to come in... they get pin feathers.. and these can be painful for the chick if squeezed or pressed. It could make them avoid you, so cupping gently over the top is recommended. Also approaching from the side and low is less scary than hovering above and swooping down like a predator. Try to encourage them to step on your hand. I highly suggest you start handling your month old birds asap... they will get used to it and it will become routine instead of freaking them out for the rest of their lives. Some will calm down and enjoy petting while others may always be flighty and only approach for treats, all are individuals regardless of breed. If you can raise them to your level it is less scary for them. For the older ones.. maybe handle individually once they have settles down for the evening. (much easier if they get dark time, so I use non light emitting heaters for chicks)
I suggest crush the crumbles extra for your new babes, it helped my survival rate for bantams.
One thing you will learn here... no one way is the right way. There are lots of ways to do things and what works for YOU may work for some and not others and that's okay. We are here to share and learn from each other. Some are more cautious, others more care free. Use your best judgement and do what seems right to you. If it isn't working or you learn something new, switch it up as needed. Chicken keeping has been a very fluid and learning always growing hobby and adventure!
Oh gosh, your new babies and kiddo are so cute!
Welcome to BYC!