Tough cookie, I think you have fairly well summed it all up. I only have one older cat, Mama cat, I think she is about 7 or 8 years old. She was the one who came to me 6 years ago, being chased by two large dogs across the yard. She outsmarted the dogs, and I put out some sardines, as that is all there was to entice a cat. She has been with me ever since. As a cat ages, they are like older people, in that they do not wander off, and go into unknown places, but instead prefer to stay close at hand by their "owner", where they know that there will be plenty to eat and can run to safety when necessary (in this case it is on the roof). They also sleep and lay around much more than a younger cat.

The first 6 months of a kitten's life is the most fun to watch, because of their play antics. After they reach about 9 months of age, they could be considered nearly full grown.