Welcome Mark! Welcome to garden web. From what you have said it seems you really care for your plants. That being said Norfolks do not always show their love for their owners as fast as we would like. You are in zone 3a I see so your plant will grow very very slowly. What you are doing so far is great except for moving it! Once you pick an ideal location (free from drafts, good lighting, etc) NEVER move the plant as that is the fastest way of killing it. NIPs (Norfolk Island Pine) grow slow and you will not see any improvement for weeks, months, maybe even a year. Pick one location and stick with it. If it's a warm bright spot, stay on top of watering. If it's a cool bright spot, you can let the soil dry a bit. I had a beautiful one I bought after Christmas December 2010. I put it outside every summer under the shade of large maple trees and a cedar hedge. In 2012 it was getting late in the season and in late September I didn't want to bring it inside yet and stuck it in my Dad's greenhouse for the night. The next day was unseasonably warm and sunny and I was at work and didn't get to it in time and by 4 o'clock the damage had been done at one side turned brown. It's still recovering from that to this day but slowly is getting better. Tip: they like to be showered with COLD water. I put mine in the bath tube once a week and turn the water all the way to cold and use the shower head and spray it.

Not entirely sure on this, but I think if the branches are still green, they're still alive. Humidity is important, but it's only part of the situation -- they also like cool temperatures and good air circulation. I also have the general impression that they don't like to be bumped around much -- if it's near a high-traffic space where people brush against it a lot, that might be some of the problem as well. The light sounds okay, as far as I can tell from your description -- they like bright light but not necessarily sun (though I have a couple small ones that do get sun for part of the day, maybe 4 hours, and they seem fine with it). It's also possible that the plant isn't being watered often enough, but I hesitate to say so because overwatering would be much worse than underwatering. How big is the plant? How large of a pot is it in?

The effects of sunburn in plants are immediate and irreversible. Sunburn is caused by photo-oxidation. High light intensity levels can cause chlorophyll molecules to rise to a more excited state than normal. If light levels are high enough, the energy that is released as electrons in molecules return to their normal energy state may be sufficient to form oxygen radicals from O2 (exactly the same radicals found in H2O2 [hydrogen peroxide]). These O2- radicals are extremely reactive particles that readily destroy chlorophyll molecules. Chlorophyll is natures sunscreen for plants, and the degree of light the plant is exposed to generally determines the level of chlorophyll present in living tissues. When we move a plant into bright light, it may not have enough chlorophyll to prevent sunburn because an increase in chlorophyll lags light exposure. The key is in manipulating the increase in sun exposure to allow an increase in chlorophyll while still keeping exposure within the protective limitations of existing chlorophyll levels. Al

I would survey plant collections there before deciding these were not present, myself. There are two levels of horticultural diversity, same as here: the general landscape, where you see the same cultivated plants over and over, and collections, where there are vastly more kinds grown. There are a great many kinds of garden plants that surely could be grown in Hawaii, that apparently aren't. For example, possibly only a single species of Magnolia, M. grandiflora is represented. Concern about protecting agricultural crops and home gardens from new weeds and insects, resulting restrictions has alot to do with it, no doubt. I've seen Trematolobelia macrostachys growing wild (and flowering) on Oahu on a prior trip, as well as a few other species I may never have identified. None this time, didn't even visit gardens. Short visit, to take care of some family business.