1) When batch editing, I think it'd be easier to have the trash can at the top after you select the emails you want to do something with. Instead of selecting the "more" button at the top. Glad the option is there but I would have to say when someone enters the batch editing, they're more often than not deleting them.
2) When hitting the delete button while looking at the email should just make it disappear instead of going back to your inbox and then having an animation of deleting said email. I can do this myself. Most people delete within the email and continue to the next one. Not go back into their inbox.
Not sure how to edit this but scratch #2 off this comment. I didn't realize that to correct this was a switch if a toggle button.