As for the gyroscope business, emcintosh and Ninja-Eule can you test this program? It's just a regular NDS application. I doubt this will work, but just as a last attempt of mine.
Start it, wait for ~10 seconds, and tell me what you see at the bottom screen (specifically, there should be something like "gyro variant" and "gyro device id"). Ideally, if the gyroscope would work, on the top screen there are 3 rectangles (reg, blue, green), and if you rapidly rotate the console around one of the three cardinal axis (X, Y, Z), they will expand up and down. You may also press DPad Up for "calibration", but it probably doesn't matter