Ive not tried La Nuit Parfum, so Ill only comment on the first two pairings:
1) The One vs TdH*.
The One is a soft, warm, powdery and sweet/spicy fragrance with god-awful projection and sub-par longevity. I really like the scent of it, but long for a stronger version. Its a fantastic evening scent, because it becomes a skin scent after 2 hours or so.
The TdH is a cooler scent the green citrus opening is often described as sharp or metallic but soon the citrus opening softens (but pleasingly, and in contrast to many citrus frags, stays around for the life of the scent) and allows the vetiver to play a more prominent role.
The projection and longevity on this (and the Parfum) is excellent. I get 12 hours and over from either version.
Despite its strength, TdH is a terrific work fragrance provided its applied sparingly. The One is a much better evening fragrance, and is a proven compliment getter from women, who seem to like the soft sweetness of the drydown.
I think youd be doing yourself a disservice if you didnt have TdH. Id suggest sniffing out both the EDT and the Parfum. I prefer the Parfum, but am happy I have both in my wardrobe.
*presumably you mean the EDT, but some of my comments also apply to the Parfum, which is a much warmer, smoother and woodier TdH.
2) Rabanne PH* vs RG
Again, almost no similarities, save for the fact that theyre often both referred to as barbershop fragrances.
This is because PR has a classic masculine scent associated with the image of the clean-cut man of the 1950s, and RG allegedly smells like Barbasol shaving cream (Ive never smelled Barbasol so I cant comment).
They smell exactly nothing alike to my nose RG is a very clean, spicy, soapy fragrance thats often compared to Azzaro PH. I also feel its in a similar vein to the Taylor of Old Bond Street colognes. Im not saying it smells like any one TOBS scent, but rather it has the same understated, soapy appeal that those British colognes have.
PR, on the other hand, is more akin (but certainly not entirely similar) to Antaeus, Kouros et al. It has an unapologetically brash opening and I feel it even smells acrid, in stark contrast to the smooth, mature RG. PR still smells quite clean on the drydown, but not in the same soapy way that RG does.
The only other similarities between the two are their above-average projection and longevity. I hear the occasional person say RG has poor longevity, but I easily get 6+ hours from it, and I feel it outdoes PR in that regard.
I bought PR because it was a good price and wont buy it again, whereas Ive got two backup bottles of RG. Its clear where my preference lies.
*I have the current formulation, so cant comment on vintage PR PH.