Generally, do you like the lore/story so far?

[LineageRazor]

Minfilia's role in Shadowbringers:

Rather than looking at it like Minfilia was sacrificing children, I saw it more like Minfilia/Hydaelyn have a limited ability in how they are able to influence the world. Much like as with the Warriors of Light, Hydaelyn EMPOWERS people, she doesn't intervene directly - Minfilila brute-force stopping the Flood of Light was a one-time exception to that rule.

So, she empowers children (girl children, likely because Minfilia herself is female) from infancy. Perhaps the intent was for these children to grow to adulthood before exercising their power, but all of them, whether by their own choice or under pressure from the adults around them, wind up taking up the metaphorical sword at an early age - and dying at an early age.

Hydaelyn is all about choice. She grants the ability, but it is always the choice of the recipient what to do with that power. Some Warriors of Light, in fact, have gone full-on villain, such as Saint Adjora, who summoned Ultima, the High Seraph.

Minfilia wasn't sacrificing children. She was granting power to children, and the fact that she was doing so indicates that she did not have the ability to grant that power to already-grown adults. She was limited in her options, and helping the world as best she could. It no doubt pained her greatly to see so many young women give up their lives, but the world still had a need for them.

Eden, and On Thin Ice:

Honestly, I think the best way that they should have handled the whole Ryne-to-Shiva thing would have been to have made it an unintentional side-effect of the Summoning. We already know that the "heritor" primals are shaped by the WoL's mindset (which is why Ramuh had aspects of Rhalgr and Ixion, and Titan had a car mode reminisicent of the Goblin tank). All it really needed was for the WoL to be subconsciously thinking "Shiva needs to have a human woman at her core", and Ryne could have been unwillingly drawn in.

[Vyrerus]

Titan had a car mode reminisicent of the Goblin tank)\

It's an ATV, All-Terrain-Vehicle. :3

Edit: Also, to me, it was more similar to the second boss in Doma Castle mixed with the armor of the last. All on top of a Titan who looks more like Raubahn than anything...