Does setting techOrder for video.js really work?

Does that help Does Windows recognise the kinect camera as a video device? If so, then the Lync client should allow you to select it as the video source under the Options screen. You'll also be able to select it programatically, but I'm not at my machine and can't remember the call to make off the tip of my head.
If not, then I think the key is getting the kinect camera recognised by windows (possibly using the kinect SDK?). Otherwise, I don't think there is a way to programatically stream video from the kinect camera to a Lync video call using the Lync SDK.

With these it helps The start parameter still works. The problem is, that you compute a wrong value for it: wrong type. Maybe it has been changed: Supplying a valid INTEGER value works. (If fractions are allowed, then not all are valid.)
For example, if you want a value between 0 and 200 then use:

  var maxVal = 200;
  var startVal = Math.ceil((Math.random() * maxVal));

should help you out The Accept Ranges header (the bit in writeHead()) is required for the HTML5 video controls to work.
I think instead of just blindly send the full file, you should first check the Accept Ranges header in the REQUEST, then read in and send just that bit. fs.createReadStream support start, and end option for that.

var fs = require("fs"),
    http = require("http"),
    url = require("url"),
    path = require("path");

http.createServer(function (req, res) {
  if (req.url != "/movie.mp4") {
    res.writeHead(200, { "Content-Type": "text/html" });
    res.end('<video src="http://localhost:8888/movie.mp4" controls></video>');
  } else {
    var file = path.resolve(__dirname,"movie.mp4");
    fs.stat(file, function(err, stats) {
      if (err) {
        if (err.code === 'ENOENT') {
          // 404 Error if file not found
          return res.sendStatus(404);
        }
      res.end(err);
      }
      var range = req.headers.range;
      if (!range) {
       // 416 Wrong range
       return res.sendStatus(416);
      }
      var positions = range.replace(/bytes=/, "").split("-");
      var start = parseInt(positions[0], 10);
      var total = stats.size;
      var end = positions[1] ? parseInt(positions[1], 10) : total - 1;
      var chunksize = (end - start) + 1;

      res.writeHead(206, {
        "Content-Range": "bytes " + start + "-" + end + "/" + total,
        "Accept-Ranges": "bytes",
        "Content-Length": chunksize,
        "Content-Type": "video/mp4"
      });

      var stream = fs.createReadStream(file, { start: start, end: end })
        .on("open", function() {
          stream.pipe(res);
        }).on("error", function(err) {
          res.end(err);
        });
    });
  }
}).listen(8888);

may help you . This is because jsfiddle is now using the sandbox attribute on the iframe the results are shown in. The effect of that varies: In Chrome the swf is loaded but Flash's ExternalInterface is blocked, so the swf can't be told to do anything. In Firefox the swf doesn't even get loaded.
jsbin's also uses an iframe with sandbox in edit mode, but works fine out of edit mode as no iframe is used.

I hope this helps you . Consider the following app (code simplified) , I guess the correct way is

document.getElementById("video").srcObject = stream

<template>
  <div class="container">
    <video id="videotag" autoplay></video>
  </div>
</template>

<script>
export default {
  name: "video",
  components: {},
  mounted() {
     navigator.getUserMedia = navigator.getUserMedia ||
            navigator.webkitGetUserMedia ||
            navigator.mozGetUserMedia;

        // Start video camera
        navigator.getUserMedia({
                video: true,
                audio: false
            },
            function (stream) {
              document.getElementById('videotag').srcObject = stream
            },
            function (error) {
              console.error(error)
            }
        )
  }
};
</script>