At this point in time the
estimated release date has not been posted, so we can't even give you an indication at this time.
I am aware of some customers who used the GDStar rating plugin with ClassiPress, but that was an earlier version, so I can't be 100% sure it is compatible with the latest release. AppThemes doesn't officially support third party plugins, so things like this cannot be guaranteed anyway.
Not sure what you mean by the issue "ClassiPress is not working with places/cities"? This is not an issue as such, it's just not a feature to have it running like Craigslist. It has been discussed in other pre-sales threads such as
this.
You could certainly migrate data with a custom mysql query, but at this stage we are not aware if there will be any built in tools for the purpose of specifically migrating from ClassiPress to Vantage automatically.
Yes you can use your own widgets. If the widget is part of a plugin though, then the official support rules apply.