G'day Polyfibre
As previously posted, 1st flights and the subsequent test flying to 25hrs, (40 if 1st of type in Aust), is a job for a reasonably experienced and current 'on type' pilot. The test pilot should have plenty of RV hours.
I've seen some 10-15 RV's do their test flights here, and all were done by pilots with >1000 hrs TT on RV's. Our most renowned test pilot, (16 RV's 1st flighted), is an 80 yo ex aggie with who knows how many hours. With this level of experience, the test pilot has time to look and check things thoroughly.
The RV-8 is always going to be a handful with 180 or 200 HP plus CSU - so you don't need passenger distractions, crosswinds, short runways, or a lack of possible forced landing areas adjacent the 'test' airport.
As for Australia - passengers are excluded from 1st flights, and also from the 'fly-off' - unless they are a qualified pilot and are actively assisting with recording numbers for the PIC. My experience is that even low hrs PPL's don't at all relish some of the fly-off stalling and stability testing - which is often quite interesting.
Just a point about the subsequent 'test' flying. Do not take this lightly, because things are just as, or even more, likely to go awry after the aircraft has had some vibration to jiggle things around. Make sure that it's decowled and very carefully checked over....after each flight until you get past 5-6 hrs.
And, if you have installed a new engine, it has to be run-in over these 1st few hours. That means high power settings, so this also contributes to the loosening off with screws, nuts and other items.
happy days,
poteroo..... (ex RV6 owner and now RV-9A owner)