• Variables are global by default, leading to accidental memory leaks, conflicts and various other fun things.
• A lack of namespaces.
• Lack of block scope (despite the fact the language has blocks), i.e:

  function a() {
  var b = 1;
  {
  var b = 2;
  }
  alert(b);
  }

  will alert 2.

Not really, no.

For the NTP pool you send and recieve time data; funnily enough the time is public information.

Switching your DNS servers to OpenDNS means you end up sending them every domain you visit, and apparently every Google search too.
Most people would probably want their search terms and domains they visit to stay private, so your analogy between the NTP pool and commercial DNS providers breaks down here.

(note: I'm not implying sending your DNS data to OpenDNS means it's made public!)