Yes the new growth is softer and lighter in color similar to other species of tree.
As the new growth expands and hardens off, it gets more solid feeling and darker in color as the chlorophyll increases in the shoot.
People will pinch back the new growth to reduce internode size between each year's successive growth and to control energy/push back growth. They will back bud along those needles on 1 and 2 year growth. Not sure if cutting back into old growth is advisable without something to cut back to.
Yes, what you've outlined above seems correct. I've been working with collected Colorado Blu Spruce for the last few years. My understanding is that if you're looking to reduce branch length and you've got weaker growth closer to the trunk, the best thing to do is cut back the branch later in the summer or even early fall, after the new growth has elongated and hardened off. You can also pinch back the new growth to new buds that you can probably see now, or you can wait until the foliage has hardened off. The new buds are small whitish bumps that run along the new spring candle. If the candle is strong, you might get multiple buds that you can use to build ramification.