You will have to redo this video after you install today's update which has been reported to increase the volume.
Unfortunately you have to chalk up the mouse hover issues to poor web design. Not all sites have optimized themselves for touch. It is possible there could be a browser side correction but the browser is just executing the code of the site.
That's not quite the case. IE on the Surface deals with this in an usual way. If I try the same thing on, say, Dolphin browser on Android. When I press the 'on event' area it becomes selected and remains on screen so then I can press the buttons or whatever again to trigger them. IE on the surface only seems to have them active when you're pressing them so that's where the problem is. Also IE is the only browser on the Surface RT so we're stuck with it at the moment.
EDIT: It looks like Google updated YouTube sometime between your post and now. I went to investigate more in Dolphin with the User Agent and now see that YouTube no longer supports the mouse over. Instead they have dropped the Reply, thumbs up and thumbs down permanently below the comment. In the upper right of a comment you now have a drop down arrow for report profile image and flag as spam. I have confirmed the change on IE8, Chrome and Dolphin Mini so it isn't on just one platform or browser. Any how Google has been changing YouTube a lot lately and it seems they have also decided to make the site more touch friendly regardless of browser.
Indeed they have change the layout and that issue is no longer relevant on Youtube (I made the video about a week ago so I added something to the description to say it's fixed. But that's one website on the internet. The logic is still going cause problems on many other pages.
vgjfelix