See here please and all your questions will be answered > http://en.support.wordpress.com/bundles/
It's not necessary to purchase a bundle to map an existing domain. You can purchase domain mapping as a spearate upgrade.
It's not necessary to purchase a bundle or any upgrade to embed videos on your blog. http://en.support.wordpress.com/videos/
The separate videopress upgrade is for uploading videos from your computer for hosting and playback directly within your blog.
Also note that no upgrdae provides anything more than exactly what is stated in support documentation.
Same Rules Apply – The upgrade does not enable the permission to use advertising, any kind of prohibited code, or upload additional themes or plugins. With the upgrade, your blog will still be hosted here at WordPress.com, which means that you will not have FTP access to your files and you will still be required abide by our Terms of Service.