Bing Search and SharePoint Results Index/Crawling?

Hi everybody and a happy new year :)

We configured the Bing search to display SharePoint results. I'm a bit confused what is Bing accessing in the backgound and found yet nothing in the documentation. 

My Question is which index is Bing using? or is there sync from SharePoint Index to Bing index?

I created a new site in SharePoint and it's findable in SharePoint but not in Bing. What is the normal time frame the results should appear?

And my last question :) SharePoint has an Full Text Index, is that index also synced/queried in Bing? can I search for my custom properties created in SharePoint? or is a mapping needed (Crawled/Managed Properties)