Hi,
Vegas started as a Multi-Track Audio editing application back when Sonic Foundry was developing their creative apps. They did some very well coded apps that were intuitive and stable on the PC platform. Video was an add on.
Do a search for Douglas Spotted Eagle. He moderates the vegas board at Creative Cow and has done many tutorials. He'll be able to steer you to some good training material. He is a nice guy, too, very helpful. And he knows Sony's Creative software better than anyone I know.
You can open unlimited audio tracks in Vegas and render them to two.
I use Vegas mostly for video work. But, I use it for Audio along with the other Sony wares, Sound Forge 9 and Acid Pro 7. Good Stuff.
Send a pm if I can help you further.
Best,
John Hartney