Just gonna comment on one point regarding Hydaelyn.

As a reminder, she never gave us special powers or w/e, just her ward against aetheric corruption (tempering), which the game flat out mentions is all the Blessing of Light ever was. She also shielded us once which was during the encounter with Gaius and Lahabanana... and that's it. Everything else was us, including the Echo, which is just an inborn gift the ancients had to begin with, so nothing is going to "fade" since there was nothing there to begin with. If we never encounter another primal again, her ward is effectively useless, and even if that fades, we now have protection in the form of those talismans Nidhana and co. created anyway. Hydaelyns' entire gambit lay in whether or not people could stand on their own without some external force/power watching over them. She never gave her "blessed" anything beyond what they already had, her ward and the ability to occasionally communicate with her.