I don't use any expo either. I used to up until last sunday when I set all the settings back to normal. I didn't find it to be very different. I have the Helios and I had settings for just about everything adjusted (expo, 2 way steering, 2 way throttle - never used the ABS as it's murder on servos).
As for the brake rod, if you set up the brake as per the manual (so the threaded rod goes into the ball end that attaches to the brake arm, then all you have to do it put an old pinion or similar on the end and voila, you can adjust the brake in the warmup.
I actually prefer to adjust it using my radio so I can adjust it during the racing if needs be. On the Helios I have the steering throw set under my thumb and the brake set on the right of the steering wheel. So if I have too much or not enough steering, I can change it in a basic way, and I can also compensate the brake pressure based on tyre wear in long runs.