Just a suggestion: change the default hotkey for the delete action. It's the same as Mail's hotkey to send a message, which I think is just asking for trouble. I hit Command + Shift + D to send a message, not having noticed the conflict in my brief look at the updated version of Mail Actions, and it triggered the delete action as well. Fortunately Mail crashed and I only lost a day's worth of messages (they were not in the Trash folder; should they have ended up there, or is this supposed to be a direct delete?). Granted, I should have been more careful, but I think it would be wise, for the sake of us fallible humans, to make the hotkey something that doesn't conflict with an existing Mail shortcut.
Thanks for the fantastic workflow!