Maybe one of the scripters can provide a script to reply to and close the
message window. You could assign a script shortcut to make this seamless.
Just heard back from Paul Berkowitz, one of the Entourage scripters....
It can be scripted if s/he is willing to use another keyboard shortcut (i.e.
run a script) to Reply and Reply All - e.g. ctrl-cmd-R and shift-ctrl-cmd-R.
It is not scriptable if he wants the Reply button or menu item or standard
shortcuts cmd-r and shift-cmd-R to be "intercepted" to do something
different.
Are you OK with using another keyboard shortcut?