Regenerate the cover - I assume they're using Generate Cover plugin. I actually have a chain to re-gen the cover + Polish Book, which would also cover Embed Metadata if they select the option.
The last one can be done with single-field edit. I highly suggest looking into the
template language as it provides some extra flexibility.
For "Send the eBook to the Kindle," do you use the Reading List plugin? If so, here's what I do. First I have a Send-to-Device list with these sync settings:
Then I set up two actions. One is to send the book to the device directly. The other adds it to the send-to-device list. Then I can use conditions to select the correct action depending on whether or not the device is connected.