At the bottom of each page is a black bar. One of the options is "Change Theme". If you click it, you get a list of available themes. Give QB 2014 a try to see how it loads without the video player - the video player is not installed in that theme.
That's not a fix, but it will tell us something. What would really help is if some members would:
1. Time the load for the main page using the current default theme.
2. Report that load time in this thread.
3. Let us know both the OS you are using, as well as the browser.
4. Multiple browsers would be appreciated, if you have them installed. Chrome, Safari, Opera, IE, etc.
Once we have a few reports, I'd like to remove the video player from the current default theme and leave it off for a couple of days. Then, have folks re-run 1-4 and post the new results.
The reason I'd like to do it that way is that the other themes not only don't have the video player, they don't have some other things we've added to the default theme. For all we know, it could be that the problem is a conflict between the video player and something in that's in the default theme that isn't in any of the other themes.