You don't need brakes and I am no help on mounts but I can offer a tip.
As you ride up the quarter or bank or whatever, ever so slightly alley oop into the tire tap so your momentum carries you ever so slightly backwards. This motion akin to going fakie will engage your rear hub and take up any chain slack allowing you to balance using pedal pressure alone.
Good luck.
P.S. Also a lot of different manufacturers have different removable lug systems, you need to either post what model and manufacturer frame you have or speak to your local bike shop distributor and by that I mean ring the Rad shop.