SteadiCamCurve Stabiliser for GoPro Hero 3/3+/4 - Silver

Can i use the joby griptight mount on the curve to hold my phone? or is it only specifically made to hold a gopro?

Does this work with the hero 5 black yet? it says it does on the website and in the description. but i see recent reviews saying it doesn't.

If I was using this for skiing, could I point it downhill, or will it stay perpendicular to gravity?

Will this work with the GoPro Hero5 (size and weight changed)?