Great Purchase Congrats! They are extremely rare!!
I absolutely love my BK9 (and G70).
The BK9 is probably one of the most underrated keyboards out there.
It has an incredible sound quality overall with amazing capability and functionality... However my experience is that it is let down by poor navigation and controls - It is not the ideal keyboard to be tweaking and making changes on the fly...
In terms of setting up registrations - its very easy to do in the Performance List section. It make take you a few attempts at getting your head around it. Sadly the Scroll wheel is about to become your best friend

There is a BK9 performance editor app which you can use on your Ipad (requires USB connection) and allows you to have a full touch screen graphical interface to manage and edit your performances on the BK9 which is an awesome aid for the BK9...
regarding the G70 and USB - Since it takes a compact flash card for memory storage, you can just buy a (very cheap) card and USB reader off ebay to get going. It has never ben an issue for me.
Best of luck!
Nick