1) I'm not aware of any specific talk of integration of this kind being included, however since the theme is still in development, you still have the opportunity to submit any feature requests in the
AppThemes Ideas Exchange if you wish and our development will take these into consideration.
2) It's not really possible since as mentioned, this theme is still in development. Some users have chosen to start with our ClassiPress theme with hopes to upgrade to Vantage later, so this is always a possibility, however you may need some knowledge of mysql if you plan to migrate posts over when the time comes, so that all fields are in the correct place.
3) This is difficult to compare with other themes, because we now have a much larger development team on board, with a stronger commitment to ensure we deliver themes when promised. At this time we don't have a set
release date for Vantage, but we expect further announcements on this in the near future, so you may wish to follow the
AppThemes blog for more information when it comes to hand.