All- apologies for being a little late to the party. I've respond to a bunch of question below, and THANK YOU to the community members who are out there helping other community members!
Also, there is a significant amount of feedback here for feature adds, particularly around hybrid AD scenarios. I'm afraid I can't respond to each of those individually, but I'll make sure they make their way back to the product team. The most direct link to that team is the [Feedback] button directly in your admin center.
Brock Brayboy- Both Microsoft 365 and Office 365 use the same admin center, so it will apply to users on both.
Alexander Lorenzo- I don't believe so.
Murray McDonald- Try this- https://support.microsoft.com/en-us/help/2617079/litigation-hold-users-cannot-delete-messages-in-office-365-dedicated
Martin Meraner- Yes.
Keith Summers- I don't believe so.
Forrest_H- Yes, the person now assigned the files receives a notification.