Yes, I use the same ID for Product (and force ID) and for importing Combinations. I use the same name for colors. Or should I use their ID? (Then that would be very complex to find and add to csv)
I use the EAN, which there is one for each combination alone.
I use Cost price impact and Price without taxes impact in the Combinations csv (In Products I set them to 0, because some sizes change price)
I do not know anything about php. I only know copy and paste.
And Update combinations or Products, do they add the new values to the old or change the old values for the new?
""Do you have the refence field (in combinations.csv) correctly filled?""
Which Reference you mean? I use spanish so I got this fields