A:Answer You don't need a separate mic to use this recorder as it already has a couple attached to it (though recording with a shotgun mic is always a plus). You can check videos on YouTube where they used the standard mic from this recorder to see if you like the sound quality. In my opinion it is perfect (at least for my purposes of interviewing) as it captures everything that is said with great clarity. But I would recommend you to make that assessment yourself.
To make it perfectly clear: Yes, you ca record sound with this recorder, and then use your camera for the video. Of course, you would then need to synchronize them on your computer.