What product fields are mapped between Magento and Vend? & Are these fields synchronized both ways Push/Pull?

1.

These are pulled up from vend (SKU, title, description, price, status) and these are required but is inputted by customer at config side (websites, tax class id, categories, attributes) 

2.

Currently it is one way, always following the values from Vend. QTY on the other hand is updated at Vend when Magento sales are sync to Vend. This updated QTY is updated back to Magento when its time to sync product info.