Changing email addresses and such should be performed against Exchange Online, not Azure AD. Plus, there is no way to bulk update secondary email via the UI tools, so you have to use PowerShell for this task.
Company can be updated directly via Azure AD, but the Azure AD blade is very limited when it comes to bulk updates though. You can go to the EAC -> recipients -> select the mailboxes in question -> click Update under Organization on the right hand side. Or just do it via PowerShell as well.