Yes. Koalas have ears, just as other mammals do, and their sense of hearing is known to be quite keen.
Unlikely. Koalas have an acute sense of smell, and cologne would be far too strong for them.
Male koalas fight for territory, females, and a sense of dominancy (higher ranking) within a group or family.
Koalas have an acute sense of smell. It is believed that this strong sense of smell lures the newborn embryo into the mother's pouch.
The Koala eats eucalyptus leaves, they don't hunt in the traditional sense, they forage.
Koalas are native animals, and are therefore not "useful" for things in the human sense. They fulfil their spot in their ecological niche, which involves the spreading of gumnuts and gum tree seeds, but they are not "used" for anything.
Koalas are not born in their mother's pouch. Baby koalas (known as joeys) are born from the mother's birth canal, and from there they crawl into the mother's pouch. they are guided by instinct and, scientists now believe, an exceptionally strong sense of smell that leads them towards the mother's milk.
It cannot be very good, they eat gum leaves, which smell nice but taste terrible. They do have a very good sense of smell. Smell is how they select which leaves to eat.
Adult koalas are simply called koalas.
Koalas are not primates. Koalas are marsupials.
Koalas do not have a home in the sense of a single, central location. Their "homes" are always in eucalyptus trees. They do not use tree hollows, nor do they make nests. Koalas nestle in the forks between trunk and branches, and shelter within the branches and leaves. This gives them adequate protection from all kinds of weather. Koalas do have a range of home trees, however - trees that are part of each koala's specific territory.
Depending on the predator, yes. Koalas have acute hearing, and can certainly hear ungainly creatures such as domestic dogs, as well as stealthier animals such as dingoes. They would be unlikely to hear a python.