E.g. I want to send a newsletter as a one to one email and use sequences but I am not able to do that. or altenanatively provide the ability to better format one to one emails so they email content can be better centered.

Workflow are very powerfull, but they can be very harmfull for your system as well, if they aren't treated correctly. Therefore, an option to simply undo all actions done by a workflow would be great!