Questions about a pod with some replicas and some conditions

Hi there, consider the below scenario:

There’s a cluster with three worker nodes. There’s one pod with 3 replicas and has pvc.
Suppose this pod is an nginx web server. I manually added a site1.conf file to pod in worker1 (only worker1).
I only ran this command after applying the yaml file and make pods running:

kubectl expose deployment testDeploy --type=LoadBalancer --name=testService

1- Do the all volumes of these three replicas have the same files? Or worker1 has file site1.conf but pods of the two other workers do not have this file?
2- When you as an end user type, which pod does get your request and which worker shows this site? Does Kubernetes automatically and based on load balancer and kuber-scheduler decides? What if three simultaneous users type
3- If I shutdown one of each workers, is the site still accessible via other nodes?