I'm fairly certain the "Direct" button on the remote is for direct tuning an AM/FM station. Although I haven't hooked up any antennae as of yet, and haven't even tried the tuner.

What can be done if more inputs are needed is, use as many connections as are available, whether they be analog stereo, digital audio, or the 7.1 multi-channel, and you could just enter the menu and switch the audio configuration for that input, whenever you're using an alternative connection. This may be necessary for only another few connections and it shouldn't be too much of a hassle for the number of times you're going to use these other devices. You would only have to switch back when moving back to the previous connection.
I guess that's what you pay more for.

The front HDMI won't override to HDMI if something is plugged into it. That would require an auto-sensing component or circuit, which isn't mentioned in the manual. (But I haven't tried that either.)