I succeed in one of my goals. We found a way to have a full hand control of all control surfaces. Yihaaa! My goal to have this glider accessable to wheelchair users is achieved!
Right stick controls roll and pitch, left one controls yaw. The lever just below the top tube controls the flaps. And i have a surprize about those flaps. But ... no spoiler info at this info. :)
The control connections are made so easy that it is impossible to connect the wrong cables during assembly.
Only two pins needed for the ailerons and two for the flaps. It could have been one for the flaps, but ...i prefer the safety of two-way-controls. I don't count on a spring or elestic band to counter the single cable action.