1. Yes, "convict" is a common name originally referred to one species, Amatitlania nigrofasciata. Today, many more CAs are available in the hobby and dwarf CAs are commonly called convict cichlid by aquarists, collectors and scientists. Technically, all CAs originated from a single lineage and can cross breed. Amatitlania nigrofasciata has been known to cross breed with just about every CA available in the hobby, so it is not far fetched to call all dwarf CAs "convict" and that there is "convict" in every CA tributary. No one would call dwarf SAs "convict" as they originated from different and multiple lineages, and rarely can SAs cross breed with CAs. One exception is a SA from Uruquay , Australheros Red Ceibal, that has been known to cross breed with "convict" apparently and surprisingly sharing a common lineage thousands mile apart. I have kept and bred Red Ceibal long time ago and they look and behave like "convict"
3. I agree that aggression in the animal world may be more correctly described as territorial. In the mammal world, predators are typically territorial as lion would kill other big cat, hyena and wild dog, not for food but to eliminate competition. Herbivorous mammal, on the other hand, are typically not territorial except during mating season. In the fish world, the opposite may be true as herbivores are typically more territorial than predators as in the case of Mbuna and Tropheus. Since given the opportunity all fish will eat fish fry, invertebrates, and animal plankton, so there are no exclusive herbivores in fish. Predators in fish should therefore be narrowly described for and limited to piscivorous. If aggressive = territorial, and predatorial = piscivorous, then predatorial behavior in fish does not necessarily equal to aggressive behavior as in the case of wimpy Oscar and Frontosa.