It seems highly unlikely that Westerners will be eating insect burgers any time soon. People will switch to soy before they switch to insects, since tofu is much more palatable than bugs. Also, "veggie meat" has been on the market for many years and there are several established brands with some fairly tasty products. My acquaintance is a big BBQ guy, and he tried some of my veggie Field Roast sausages and said they were really good. He was surprised.
As for seaweed, I think with the increasing popularity of Japanese foods, I think that has a good chance of gaining widespread acceptance. Already workds like nori and kombu are pretty well known by the public.