Allow true custom shortcuts
Gmail allows remapping the shortcut keys (I remap "go down" from 'j' to 'n' as I use an alternative keyboard layout). It'd be great if Airmail either read the shortcuts I use or allowed me to remap the vi-style ones as well as the system ones. Also, '?' should bring up a list of shortcuts. That's a very handy feature that Gmail, Facebook, and GitHub all use.