RE: How much expo???
Flying here at 5400ft with a DX-7, and when I am setting up a new 60 size airplane, I generally add about 15% more throw and start with -25 expo on all surfaces. During the initial day of flying, I add or subtract as I feel comfortable with.
Most of my stuff will be Tiger 60, Utter Chaos 90 (Bridi Design), BTE Delta Vortex, etc. I am a sport flyer and do no 3D flying.
Cheers-Tom