The "soon to be released" VS 10 will answer your prayers with more tracks than that!
However in the meantime you have two with VS. The actual video track and the overlay track. A "cheat" is to render smaller sections of you video as you go. That way you can just load the sequence where you need more than two tracks, do what you can with the two available tracks and render it. Then load that new file back into the timeline in the video track and add your third asset into the overlay track etc.
The other option, since you mention other Ulead products, is to upgrade to Media Studio Pro -- though this is an expensive product more at the professional end of the market. It offers multiple video tracks, amongst a host of other features. As with everything, though, there is a learning curve. But if you are familiar with Video Studio, then the basic approach is much the same in the fundamentals -- though it can also do many things that Video Studio can't and does some familiar things in slightly different ways. As with all Ulead products, you can download a trial and see if you like it.