WRT the first one "Yes, you own the rights to the content you create and post on dev.to and you have the full authority to post, edit, and remove your content as you see fit." which on the surface seems a lot better than many crowd contributer situations.

WRT the second one I still don't know and if there's a wikipedia page for dev.to I can't find it.

On the whole dev.to seems better than medium, for now at least, and more approachable than using gists.