You can try using the getDuration() and getCurrentTime() methods on the youtube player object.
On an event, use this custom action:
var ytp = document.getElementById('gwd-youtube_1');
console.log(ytp.a.getDuration());
console.log(ytp.a.getCurrentTime());
where ytp.a is the minified YouTube player object and the youtube component id is gwd-youtube_1
Hope it helps.
San
Google Web Designer team