Winkie131
I would wait and cut in the early spring. If you are looking to create a bushier plant, cut down to about 12-15 inches on the main trunk. This will sprout new branches quite soon at that time.
Depending on the length of the top section, I would say root it in its entirety.
You have a nice pink variety that somewhat reminds me of 'Miami Rose' - I'd need to see more close up pictures of the bloom to be sure. This variety tends to be a tall grower.
A well-balanced fertilizer will help your tree to produce blooms more than once every three years. And - I cannot say this enough - Plumeria like to be in FULL SUN.
