A few thoughts:
* Join EAA to get access to additional support. VAF and EAA each have advantages;
* EAA has just come out with a guide to flight testing, including test cards and a full test program. It's voluminous because there's lots of relevant material. I'm not sure if the rule has been implemented yet, but if you use their guide, you may not need to fly a full 25 or 40 hours. Well worth the cost;
* Get full operating limitations and guidelines from the folks who custom built your engine;
* EAA has a Flight Advisor program (I'm one) to help folks plan their flight test program. A good Flight Advisor can help you a lot;
* EAA also has a program where an *appropriately* experienced pilot can fly with you on the first and subsequent flights. The experience and recency requirements are steep, including time in the same make and model. For example, I meet the requirements for RV-9A but no other;
Getting into more nitty-gritty:
* Vy is determined in flight test. There are references to doing that, but if your avionics have data recording, you can probably do the job faster and easier, although I've not seen a reference;
* In climb, the factors you trade off are engine power, cooling, fuel flow, airspeed (for getting somewhere), cabin noise, outside noise, and view over the nose. Carbureted engines typically run extra rich at full power for extra cooling. With your cowling, you may need to climb faster than Vy for cooling. (Even the lowly Cessna 150 at one point recommended climbing above Vy for engine cooling). And being a good neighbor (prop noise) may mean a power reduction right after takeoff;
* One of the tradeoffs in light airplanes flown in the ATC system is speed variability. Sometimes you slow down for traffic, sometimes you speed up. Yesterday, for the first time in my flying career, ATC asked me for minimum speed and maximum speed on the same approach! A significant goal on approach / pattern is to always have the airplane in trim, and if you deliberately fly with changing speeds (sometimes you have to), make sure that you have the airplane in trim long enough before the flare to be comfortable. The same criteria that you use in other airplanes (start with the book values, modify as appropriate for the situation you're in) apply to the RV-10.
One of the key points that Rutan advised in the days of the VariEze, when transition training was not available, was to get really good in two dissimilar aircraft before you did your first flight. That's still good advice, even if you get type-specific transition training, and that is available for the RV-10. (I could not find it for the RV-9A and wanted it, even though I had 3000+ hours, ATP/CFII).
I'll be at Sun n Fun and we can chat, or if you prefer, PM me your phone number.
Ed Wischmeyer
EAA Flight Advisor