Extending on-premises AD to Azure

Hello,

I am in the process of extending on-premises AD to Azure. I have couple of questions regarding the build and configuration;

1. I hear Microsoft recommendation is use dynamic address for the VM and the IP won't change for VM's built using ARM. Is it okay for the AD VM in Azure to have a dynamic address?
2. I built the VM, however I added the on-premises DNS servers in the interface properties while logged in to the VM. Once I manually entered the DNS IP address, I cannot RDP in. How can I remove the DNS entries I entered manually?
3. Is there a workflow for extending on-premises AD to Azure?

Thanks in advance

TIA TP