Regarding Sasha talking about Eteri's team limiting the number of quads she jumps, this is not news. Sasha has said many times in the past that she wants to keep jumping, and Daniil says that they have to stop her and limit her freedom in that area. They just have fundamentally different approaches to the sport, and from what it sounds like, they were no longer compatible. Just like the quad vs. artistry debate, every athlete is different and has their own opinions on which parts of the sports they prefer.
If Sasha wants to focus on her jumps, then that's what she wants. She's still a figure skater, just one who is much stronger in the jumping portion than the others (artistry, spins, SS, etc). Just like if another skater is a better spinner or artist, and weaker in jumps, they're still a figure skater. Some fans prefer jumps, some prefer other things, but only the scoring system decides what they value more in terms of competition which is the biggest goal for these athletes.
Given the comments from Sasha, past and present, it doesn't surprise me that she left Team Eteri. She doesn't want to be limited in her quads, and the team wanted to limit them and work on other areas. They had a difference in opinion regarding her skating, and Sasha left for another coach that is more aligned with her priorities. Regarding health and safety, she and her parents have the final say. Of course, a coach should try to protect their athletes and take measures to limit injuries, but that's just from the POV of the coach; the other side is what the athlete wants. Plus, jumps aren't the only elements to injure a skater. Maybe for Sasha, given her body type and skillset, it could be more likely for her to be injured from spins? She would know best. The athlete also has the final say on how much risk they take. Either way, it's not a crime to focus on quads, it's just the part of the sport that Sasha enjoys the most. No one is complaining that Anna or Alena are "too artistic". And as far as injuries go, they've been injured much more than Sasha.
I also think it's naive to assume that Sasha isn't looking to the future, or she doesn't understand that the risk of injury is higher if she jumps more quads vs. not jumping them. It's not a difficult concept to grasp, and I don't think she's an idiot. But there is a risk from just figure skating at all, jumping singles, doubles, triples, and the upper limit is different for each skater and they all have choices to make. Maybe Sasha knows the risks but is deciding it's worth it for her passion for jumping? And so she went to a coach that also thinks it's worth the risk (injuries, not qualifying to Olympics if she bombs, losing medals if she bombs).