I'll just answer some questions about locations (which are basically the same during Magnum time as well as today). Obviously you all know that a show is not shot in the order that you see it completed on your TV. All scenes pertaining to one set are shot at the same location--different scenes but same pertaining location. Costume changes, day/night changes, happy/sad changes, clean / dirty, or sunny / rainy all shot at the same location on any particular day. If there are a lot of scenes at this location, maybe 2 days. It takes, on average, 6 to 8 days to film one 50 minute TV episode. "Baywatch Hawaii" took 5 days, "LOST" takes 10 (or more). The general rule is to be "out" on location as little as possible (3-4 days max) and "in" on the soundstage as much as possible per episode. It's not only cheaper to be onstage, but you have greater control and convenience for everyone.
So to answer the question (I hope), it is possible to make major moves on this island, but not on the same day. Filming on the beach in Mokuleiea on Tuesday can be followed by a house in Hawaii Kai the next day. You would never make a move that far in one day even if those 2 scenes followed each other in the script / plot.
Next answer, yes, there was (and is) a tendency to use the same locations for different scenes / sets over and over--sometimes even in the same episode. The front of a house is where the good guy lives, and the back of the same house is the break-in scene for the bad guy's house. Obviously "film friendly" locations with an easy to work with owner, plenty of parking, cheap, secure, multiple looks in one location, near town would be used much more often than a difficult to get to, problematic owner, expensive, or too close to a rainy area, etc.
Generally homes of crew or producer ("above the line") members were almost never used in filming. First, there could be a conflict of interest with the studio that the producer was using his home or property (and getting the location fee) because of his influence rather than appropriateness of the location. We did film once at Tom's (and other owners) club, "The Black Orchid."
Second, ANY person who works on a film crew would know the kind of abuse a location takes--even when being watched carefully. Let's just say that not all of the 100+ people who work on a TV show crew are as careful as considerate as the owner would be.
Third, there is sort of an anonymity or privacy among crew / actor / producer people. Do you really want everyone you work with inside your bedroom or the set dressing crew moving and finding what is really under your sofa? No. You really don't even want anyone to know where you live!
I refer to the film crew as a "city on wheels" in a former post. That means the bathrooms, offices, food catering truck (breakfast, lunch and dinner for 150 a day is not uncommon even in a swamp/beach/valley location), trailers or motor homes for all featured actors, 30 and 40 foot trucks that carry equipment from light bulbs to 12,000 watt lamps. ( No 60w energy saving fluorescents for a film crew!), wardrobe with double and triple outfits for every main actor and all sewing, steaming, and cleaning possibilities, and 1 (or more) giant generators that could power your entire neighborhood in a blackout (except that you wouldn't be able to afford the rental!) a prop truck not unlike a small K-Mart, and even a portable gas truck that refuels your vehicle. Sometimes even a special effects truck with enough explosives to really make a big mess. I'm sure there are towns smaller than a location TV show. Feature films are even larger. You could live inside Bruce Willis's portable gym trailer!
So given the above abilities and production needs, it would be very rare to ever use the power from a home or small building to power all of this equipment. When filming on a 25th floor of a building, however, the electricians would work with the building engineers to tie into their power rather than run cable up all those floors. Imagine your bathroom with 150 strangers using it in one day?!
And the final answer is, yes, the only thing more fun than my house at Halloween is my house at Christmas! I think I'd better save this topic for another blog and get back to Magnum, P.I.!
As far as getting to the set each day, guest actors and many resident featured actors were picked up at their hotel or homes each day by a teamster driver. Tom lived so close to the stage he could have walked or ridden a bike. Obviously for security purposes he drove or was picked up by his driver (who is still with him 20 years later) or his security man. Most of the actors would stay at the Colony Surf or if VERY big, at the Kahala Hilton Hotel (now just The Kahala). Sometimes Tom rode in his motor home out to a location. Did you know that one year he gave all his co-stars new Porches? Are they cheaper by the dozen??