When you say seed oils are inflammatory, and therefor, something, I am genuine curious about where you got that information. What does consumption of seed oil lead to and what does the data say on health outcomes for people who consume seed oils.
The thing is, we went over it earlier, sugar consumptions has decreased in the last few decades while obesity and metabolic diseases have increased. Clearly, sugar in large quantities are unhealthy especially if you're overweight and physically inactive, but I don't see how banning HFCS will make a difference specifically, nor that people wont have plenty of opportunity to consume other sugar alternatives. There is nothing inherently special with HFCS on metabolism.
I don't disagree with banning certain toxic food colorings, I think it'll probably make a modest, but not entirely insignificant, difference in things like some cancer rates. I just don't see how it'll have any impact on the main issue of the obesity epidemic.