Nothing could have prepared me for what happened tonight...it is my own fault for not preparing and doing the research beforehand. I have used The Setup Machine rig by Anzovin in the past so am very comfortable with using it and ideally would have used it for Caruso's animations if I was going to hand-key the animation. I have never used mo-cap data before so my knowledge is still very limited for what was needed to prepare a character mesh for motion. A brief search on Google showed up some posts about how The Setup Machine rig was a little too "heavy" to use with motion capture so I decided to use AdvancedSkeleton instead as it looked like a much simpler rig. In fact - that's a little too complex for what I needed too. In fact, it's probably impossible to use with motionbuilder but it was very difficult to find relevant search results on Google.
The first problem I realised was that Caruso's mesh needed a skeleton. However, the way the AdvancedSkeleton tool works is it creates half a skeleton then mirrors it. But in the navigator, the entire skeleton is not listed in the hierarchy under one common parent. When I check the outliner in Maya I had to search through the lists for joint icons and try to correspond it to the Motiobuilder navigator but much of it was guess work...
I'm pretty sure I didn't do it right:
Maybe I just found the wrong things to characterise...but it's far too confusing to find the bones within the mess! After many hours dedicated to troubleshooting on the Internet and watching some more videos on Youtube I realise that all I really need to do is to apply a skeleton to Caruso and sort out the skin weights. I wish the AdvancedSkeleton rig worked though...the set driven key for the hands to clench would have been a nice shortcut to use. Ironic how much time and work I wasted for this little shortcut [that I don't get to use anyway].