Saga, this lad is a newbie. I bet he may barelly even have a clue what you are talking about with all that technical jargon. :]
But yes, trackers are in theory just as capable as a sequencer, if not more. It's just two different mediums but with many things in common. If you have the creativity, the tools and the imagination, you can create professional music dependless if you use pen and paper, a sequencer or a tracker. It's all up there in your head.
About the vocals, there are plenty of ways to create those. In fact, you do not even need to be able to sing yourself. You can let your computer sing for you! Of course, finding a virtual singer is not the easiest. The only one I know you can use for free is Virtual Singer that comes with Melody Assistant - which is a sequencer.
If you got the time, you can use a vocoder and record whatever voice you have and then modify it to sound good. It will probably sound a bit like the lyrics in Boten Anna, though, and also require quite a lot of time and technical insight. But hey, it's an option!
The cheapest and easiest way is just to record someone or yourself singing and put it in fresh and raw into the tracker. Not everyone has the voice of a winner from American Idol, but hey, with the right mixing, maybe no one will notice that you sing like a crow.
Just have fun if you get into it and see where it takes you. There's no limit to the options, you know, so if tracking does not work for you, just try something else.
