12020 question

I am installing at 12020, UBEC with plans for an 8XL when they are in stock.

Set up thus far: MIP CVD, Steel Idler Gear, Strobe Slipper, Power stroke Shocks - other wise a stock E-Maxx including radio and receiver. 12-14 cells.

questions:

I found the receiver pack jumper, but I can not find the BEC jumper. The info I have says it is behing the reciver jumper, but I can't find it. Do I need to trim back the shrink wrap? Where is it located? Will the void the warrantee?

What is the purpose of the receiver pack? Is it needed?

Will this work with the stock radio system?

Thanks!