Before I respond to the requests, just know Deepbot was meant to be a Twitch bot with integrations for an all in one bot. With that being said, the developer has the final word on what will be added/won't be added.
1. I like the idea, and think it would be great. Maybe not great for channels that have a lot of users that will be joining, since that would be a lot of spam.
2. Not too sure if that is possible (depends on discord api). Would be really kind of cool for channels that are not partnered with twitch.
3. Might be the same as the 2nd one.
4. Might be possible. Again, it depends on discord API.
5. Would be cool for users interested in statistics. Again, depends on discord API.
As for the whisper, it is possible. Could make a command with /discord in front of it in the command message so it only goes to discord. But users can PM commands to the bot on discord anyways as well.