Hi, for #1, make sure to add your repository credentials in the Infrastructure->Registries Rancher menu. This will ensure that your hosts all have access to the private images.
There are a few discussions of CI/CD using rancher in these forums, for example this.
For 3 and 4, could you provide more details? If you are trying to run the rancher server behind an AWS load balancer there is a manual step you need to do to get it to work.