sounds like you have the right information, even if the explanations aren't...well... exactly right.
Yes, the 48 hours of darkness is a good thing. Yes chopping in the morning is a good thing. Yes, a MH bulb will help increase trich. production.
The reason isn't that the plant "thinks".. anything. It has to do with the chemistry of THC and how it breaks down. Light, heat, and gland disruption are the causes of thc breakdown.
So, If you throw your plant in the dark 2 days before you harvest, light doesn't breakdown the THC that is present in the trichomes. Plants don't immediately react to ANYTHING. leave a plant without water for a day in hydro and water it.. and ta-da.. it's fine in 10 minutes. Over nutes, takes 3 days to show... So the same holds true with production of THC in the gland heads.
The trichomes are believed to exist on the plant to act as a natural sunscreen holder for the plant. It's a natural defense for the plant to it's environment. The plant constantly produces THC to act as this "sunscreen" as light will break it down and degrade it.
You put your plant in the dark 2 days before you harvest and the THC present in the trichomes won't break down from receiving the last 2 days of light. Your plant keeps producing THC as it's not "aware" of the environmental factors immediately and takes a few days to adjust to it's situation. So, to put it simply, you have an extra day's worth of THC in your plant. The problem with pushing it into anything longer than 2-3 days is your plant is going to start stretching out again as there's no light.. so your buds will get fluffier the longer they sit and the plant having no light to facilitate celluler function.. it will actually start to die.. the leaves and stems lose their turgor pressure and seem to be sloppy trying to manicure... personal opinion I'm sure, as I've not seen it mentioned before, but, I find it makes a difference.
chopping in the AM is the same thing.. before your lights go on ... so you don't lose any of the THC that the plant has built over the last dark period.
MH bulbs have more UVB light in their spectrum than HPS, so if you use it at the end of flower it makes the plant produce more trichomes to protect itself and the UVB itself makes the plant produce THC to protect itself. The other side of the coin, is using MH bulbs make the bud a little fluffier than under HPS.. it's noticeable. Trust me. I grew my first 2 crops under MH and a week and a half away from my first harvest under HPS, and the nugs are bigger and tighter than the same plant (all are clones) under MH in the same conditions.
Hope it helps.
Throw them in the dark for a few days,
if you can't, chop them in the morning before lights on.
Flush your plant.. Yes it does make a difference. I do it for 3 days before I pull and it's night and day difference in taste.
You have the right answers, it just sounds like you want more people to back up the answers already provided.. and it seems to be all good bro!