In regards to your first bullet, one of Parse's competitors, CloudMine, allows developers to write their own server-side JavaScript code that executes within a sandboxed environment: https://cloudmine.me/developer_zone#code/overview
Got your point, but I think Parse.com's goal is to provide a data persistence service for Mobile developers that DON'T want to code anything on the server side. It's a simple persistence service, why would I code anything on Javascript in a third party/hosting or SDK like Cloudmine if I can do the same thing in Heroku or Joyent using the full power of Node.JS? :)
I build a Cloudmine app yesterday at a Hackathon. Setup was very fast and early one we didn't have a need for server-side processing. But then requirements evolved (as they always do) and we found the Javascript hooks very useful.
Speaking as someone who has never used node.js before, it was nice to not have to worry about setup and just start coding.
