I think that the foreshadowing was fortuitous rather than planned. "Someone will have to watch that one" could simply mean that he needed to be watched so he wouldn't tell what he'd seen. And the similarity of Duncan's father claiming he wasn't a natural child could have simply been the ordinary sort of parallel that television shows often do as a narrative device. It turned out to be useful. As I said, fortuitous.My one data point in favor of Ritchie's immortality not being planned from the start is that Duncan showed no willingness whatsoever to humor Ritchie's interest in training or martial arts, but put him off instead.   See 1 other reply

Immortals can sense others, even prior to their first death, by way of the "Buzz", though it's doubtful that those unawakened Immortals can sense the presence of others.They are born Immortal -- it's something genetic, perhaps, or supernatural -- and this power is "awakened" after suffering a violent death. I believe it was discussed at one point in Endgame (which basically sits astride the line between what I consider canon, namely the first movie and the television series, and what I consider nonsensical, which is the second, third and fifth movies) that if the Immortal isn't killed violently, but grows old and dies of natural causes or of an illness, they will die a mortal death and never become a full-fledged Immortal.   See 11 other replies

Not exactly the same. The key is that the Immortal's aging process will halt, regardless of their current period of development -- e.g., Kenny is trapped forever as a child. There's reason enough to believe that, aside from the aging process, their anatomy combats anything potentially harmful (disease, poison, toxins, etc.); however due to the fact that they can suffer a mortal death suggests that their body is not necessarily frozen in time, as one would expect from a vampire, for instance. Aside from violent death, Immortals can die of thirst, starvation or suffocation -- they'll revive afterward, of course, but it's still possible. This is why they still eat and drink and breathe. Accordingly, it's entirely possible that their bodies can gain/lose weight and muscle definition. Because their survival hinges on their combat skill, it's necessary for them to train and keep themselves in top shape, though I expect Duncan would do this regardless. While they have accelerated healing capabilities, they can't regenerate lost appendages; it's doubtful that they could re-grow an internal organ, though they seem to repair the same way as a surface wound would (with all of the gunshots Duncan's taken over the years, many bullets must have punctured his heart, lungs, kidneys, etc). I wonder what happens to the bullets?A more curious question is Immortals and their mental health. Their regenerative abilities apparently do not extend to repairing nerve imbalances or any abnormal mental activity. Many of the evil Immortals are depicted as insane, though perhaps they were insane prior to their first "death".   See 4 other replies

The immortal's physical body will be the same from the day of his mortal death until his immortal death. Kenny had a perfect episode to display this.   See 4 other replies