Mark has said that his Hamilton choreo is by
Jim Peterson, so no worries that Rohene "gave away" anything.
Yes, Mark formerly skated pairs, although his new Hamilton program is for him as a junior man.
IIRC, his pairs partner and he were not able to compete at 2017 Nats b/c one of them was injured.
I really appreciated the tone of Jason's introductory video

on his YT channel.
As entertaining as Jason can be when he is bouncing off the walls with energy, I enjoy his "quieter" side as well.
Sorta reminds me of his well-done lesson for Tarah Kayne's channel. Jason was his always-engaging self, but he took it seriously that the main point of the video was not to entertain, but to be informative about how he manages his hair.
(BTW, perhaps an idea some day for Jason's own channel now would be to give a follow-up with his techniques for his man-bun

, which I think suits him very well.)
Look forward to seeing the mix of content from Jason

. His versatility surely will be an asset.
[Although I would not want Jason to over-extend himself, esp. in an Olympic season, I do wonder whether his YT channel will mean a hiatus from his stints of blogging for IN. He is a good communicator with the written word as well as on camera.
But of course, Jason should do whatever is most gratifying to him. I certainly would not want him to feel pressure to take on too much.]