Because of site maintenance or they are updating servers
yes.. it creates bandwidth, you can keep the videos by downloading them off a site though if their really that good
It depends. If the software you we're updating is from a trusted site. Then it is safe to update your software/computer.
Google keeps updating the look of Gmail. It is because of the updating needs of the users. They try to keep updating with the latest technologies.
You can't open the site sometimes if the site is temporarily down or is updating.
There is no such thing as a YouTube site manager. It is a fake term used by trolls on youtube who try to intimidate other people.
Keep updating the browser.
You can update a HTML site by updating it's content. Changing HTML will change the content of page.
It is just as easy to get to the youtube web-site as it is to get to the wiki.answers web-site. Anyone with a computer can do it.
Youtube.com is a video site where you can upload videos of your own but another site like youtube is videojug.com where you can also upload videos
Tweeting.
Because they maybe updating the site , changing name , just wait and you will see it will be fine !