Thank you for using Syncfusion Products
#1) if I enable panning on SFChart is there a way of getting the current offset along the primary (X) axis as the user scrolls?
Using Scroll event, we can get zoomposition along with you get the axis instance, we have achieved your requirement to get the ZoomPosition and primary axis details using the 'ChartScrollEventArgs'. Please find the sample from below location.
Sample : http://www.syncfusion.com/downloads/support/directtrac/138650/ChartSample-200239824.zip
#2) SFChart.ZoomPosition might hold this value but with panning enabled and zooming disabled it appears to remain at 1.
We are unable to reproduce the issue and only axis instance contains ZoomPosition property. The value of this property reflects the current scroll position.
#3) the only documentation I can find provides no useful information
Currently, we are working on UG documentation and we will publish it as soon as possible.
Please let us know if you require further assistance, we are happy to assist you.