Macbook Pro early 2011 Thunderbolt to USB
Looking at the Traktor Pro 2 Specifications page, doesn't have any requirement that the USB port must be bus powered or host only.  In fact, they even state there is an optional Power Supply available:



So, the PS is only required if you can't get the 5V .5A from the bus (host).  In this case you have a couple of options


Use the Power Supply
Use a powered hub


As for going Thunderbolt to Firewire then to USB, I am a proponent of using the "right tool for the job."  Can you do it?  Yes.  But it's a bodge.1  

Insead, go directly from TB to USB with a  [Thunderbolt to USB adapter][2]



Finally, you never did say why your USB connector doesn't work nor which one. In my experience, it could be a very inexpensive fix to repair the connector.  This is definitely something you should look into. 



1 Bodge:  Verb. 1. To do a poor job or repair. 
2. To cobble (something together). E.g."I bodged together that furniture out of driftwood and old egg boxes." From A Dictionary of UK slang.