Do you have any bridal shops near you? What about a trip to see some 'in the flesh' so to speak. You could have a good look at various finishing treatments and even perhaps get some ideas from the staff?
I made my daughter's veil, but it wasn't scalloped like the one in your picture. I didn't serge it, as she wanted a narrow lace edging on it. The net doesn't usually fray much, so I just sewed the lace to the raw edge. It's still OK today, 20 years later.