In order to be sure of the filename & date that a chart was produced I
have to datestamp it with a text field containing:

TEXT(NOW(),"YYYY-MMM-
DD")&MID(CELL("filename",A1),SEARCH("[",CELL("filename",A1))
+1,SEARCH("]",CELL("filename",A1))-SEARCH("[",CELL("filename",A1))-1)

I then paste an image of the chart in PPT.

This means that the chart is referenced in no matter which
presentation it is used.

1) Is there an easier way to do this?

2) Can the image resolution be adjusted with a registry entry like
"ExportBitmapResolution" for PowerPoint?

Yes this is an Excel question!

Steve