^^ good point. Haven't thought of that.
Edomae just means something like "Tokyo style" (Tokyo used to be called "Edo" in the samurai days). Today, the main characteristics of Edomae is that the fish are supposed to come from Edowan (Tokyo bay area) and each piece of fish is supposed have some work done it by the sushi chef (like curing or additional cutting, etc.). Also, the sauce is already put on by the chef rather than the customer dipping himself. The edomae rules are somewhat flexible these days.
"Hikarimono" just means something like "shiny stuff." So fish that is shiny like mackerel is called hikarimono. In Edomae some hikarimono like "kohada" is cured in vinegar, sea weed, etc.
Aging the fish is just something the chefs do to serve the fish at optimum umami. Actually a lot of fish doesn't taste it's best right out of the ocean. Fish like Tuna is aged for a pretty long time (not frozen). There's a place in Tsukiji I like to go to that sells just tuna. What's interesting is that there is a display case behind the counter with the best tuna from all over Japan and they are aging the tuna almost like how a butcher would have aged beef hanging in the display. When we buy from him, depending on the aging, he will say something like "this is ready to eat right away" or "please wait several more days before serving." Other fish like snapper are aged by wrapping in cloth and put in refrigerator for a couple of days. Things like squid are probably best right out of the ocean, but I am not 100% sure.