In answer to your questions:
1) Google rich snippet microdata was implemented in v1.3.1 of Vantage
2) You can allow embedded YouTube code in the listing description as shown in
this example listing in the Vantage demo.
3) There is no specific feature for this, so it would require customization on your part if you were looking to add an indicator of some sort. Our themes are not encrypted, so you are free to make modifications if you wish. Thanks.