Is it possible to switch audio tracks in a video?

Hello! First off, let me say that I'm very new to Unity, so please bare that in mind. I have watched the tutorials, read a great deal of documentation but yet have no actual experience. That said, I am currently working on a project that requires the playback of a video clip. BUT - and of course there's a but - the video hast to be played with up to 5 audio tracks (in order to avoid creating 5 videos, one with an audio track each).

Now, if I were to solve this problem in any other environment, I'd either use a video file with multiple audio tracks embedded, or just play an audio-less video and an audio file separately. However, I do not know if either is possible with Unity.

So, my questions are:

1) Does Unity support video files with multiple audio tracks?

1.a) If so, is there a way to switch between audio tracks through code?

1.b) If not, is it possible to play back a video and an audio asset simultaneously?

2) Is it possible to start playing an audio track (or video, for the matter) at certain point in time? Like play only from the 00:30 mark to the 01:30 mark?

I am using Unity 4.5.1f3, if that helps.

Thanks in advance.

Cheers!