You'll be fine with the springs you mentioned. Only way i could see it being an issue is if you were driving around scraping your H-pipe and with so much negative camber on your front wheels you could drive on your side. Only then will you grab the attention of inspection personell and/or cops who will ticket you.
I've never seen insurance people go to an accident and measure the ride hight of a car only lowered 1"-2" at most.
The key is subtleness, and a small drop like that won't make a huge impact on the vehicle in an accident or enough to notice. Besides, the Ford springs have Ford part numbers on them anyway, so it would be hard to tell.
Now if you want to spraypaint your taillights black or drive around with blinding HID headlights and get into an accident, you could be found partially responsible.
Apparently it's ALSO illegal to drive with our fog lights and ambers on even during broad day light because ""they are parking lights""
got pulled over by a sheriff for it
Im pretty sure there is a minimum distance from the center of the headlights to the ground as well. I know they had a show on MTV about street racing and the cops where talking about that.