Using iCloud Mail with an email address based on a custom domain ?

Hello,

I have an Apple Account whose email address is based on a custom domain : myname@mydomain.com

Another company is currently the mail service provider for this email address.

But I would like iCloud Mail to be the mail service provider for this email address.

From some research, I understand that I have to proceed as follows :

• Subscribe to an iCould+ plan, which supports custom email domain

• Create beforehand an email address based on the iCloud domain : myname@icloud.com

• Add the email address based on the custom domain : myname@mydomain.com

• Set myname@mydomain.com as my primary email address for iCloud Mail

• Change some DNS records at my domain registrar

Q1. Is it actually possible to set myname@mydomain.com as my primary address for iCloud Mail ?

Q2. If myname@mydomain.com is my primary address, then where would myname@icloud.com still appear ?

Q3. If myname@mydomain.com is my primary address, then may I remove myname@icloud.com ?

Note: I want to use myname@mydomain.com only, and I do not want to use myname@icloud.com.

Thank you very much for your help