Improved Message Editing and Deletion

This seems like a lot to ask but features similar to this exist in many other programs or shouldn’t be too complex to add. At the top is a list of the features with descriptions and example use cases below. While some of these could be done with bots it would be nice to have a better system. I could see many of these features being used in communities of all types and having practical uses besides the ones provided. 

There are several main things that I would like to see:

• Edit and Delete reasons
• Edit history
• Edit cooldown / limit / timespan for edits
• Hidden messages
• Messages visible per user / role / set of users — only for bot use
• Message expiration

Edit and Delete Reasons: An explanation of why the message was edited or deleted. 

Edit History: See changes made to the original message to catch people covering up disallowed content

Edit Cooldown / Limit: stops spam edits

Edit Timespan: Stops people from editing messages days later removing information from the original message. Also, makes sure people see their message since a message edited a day ago in a busy channel would not be seen. 

Hidden messages: Hide messages without deleting them to preserve their contents. could be used to flag messages for deletion — could be used by bots (human review), report system (hide potentially offensive messages), etc.)

Messages visible to certain users: would be great for bot responses without using DMs (some users don’t check DMs or have them disabled)

Message expiration: Channel setting or command that would make messages self-destruct after an amount of time. Could be used for bot command channels, bot responses, and other channels that don’t need messages preserved.

Permissions could be used to control this and allow bypassing certain features or having certain features disabled in specific channels.