regarding point (2) I feel like https://gist.github.com/ fulfills that requirement.

With a gist you're able to quickly and easily upload a single file script (or multiple files).

Also once created you can clone it as a git repo and make updates and push back to it (e.g. add files etc). Also people can fork your gist just like git repos.

I like this approach rather than creating a "new repository" on github for small scripts or snippets because then your github profile doesn't get cluttered with small snippets and script repos and is reserved for actual "project" repos.