[Sirth]

Spoiler for Awakenings, and Yoshida/ Eita musings.:

Somewhere back, someone was wondering why the normal humans (Yuuji, Satou, Eita and Yoshida) can remember those that "don't exist." My guess is because they've awakened to the world, so the idea of the loss of existence doesn't affect them.

Yuuji: When he met Shana and told him he's a torch. Saw a boy disappear from his mother's hand, and she walked on. Same with another boy and his friends.
Eita and Satou: When they met Margery and learned about the world.
Yoshida: When she met Khamsin, and used the monocle on a boy as he disappeared (I think he disappeared...)
Ogata: Hasn't seen anything of the above, so she doesn't remember Fumina. Thus, she hasn't awakened like the others.

So I'm thinking, when you come into contact with a Flame Haze or Tomogara, and then you learn about the existence of their world and the torches, you then "awaken," and the traditional effects it would have on you disappear. However, you now have to live with the knowledge of this world, and your ignorance of it goes away. Ignorance is bliss, or so they say.
Course, doesn't apply to Fuuzetsu. Yuuji is a mystes, Eita and Satou had a spell cast on them/ have an item off Margery, and Yoshida has a charm from Khamsin. Obviously, Ogata has nothing.

As for Yoshida's "whining," I think it's because she loves Yuuji, but that built when she didn't realize he could disappear at a moment's notice. When she found this out, Yoshida's worries multiplied, and now has to deal with the fact that her rival, Shana, takes Yuuji deeper into a world she can't be part of, unless some happenstance comes about.
I think anyone would brood over the fact that someone you care about deeply is starting to get into something you can't be a part of. She's just walking into a world that is becoming more and more complicated, and she's not the type that would cope with such a thing so easily. Like the above, she was probably happier with her ignorance.
Eita and Satou probably could. However, despite it being fixable, Eita just saw the love of his life get essentially "killed" by someone he admired the most. I think anyone would at least be disturbed by something like that, but to see it happen to the real person despite frozen time, they could flip out. Seeing her in another fuuzetsu then reopened that wound. He's backing out before it happens again.
Satou is just that way. He's a composed person. Yuuji probably just has hidden courage and will he's never been able to see before, and is trying to shed the wimpy side to bring it to the surface. Can't wait to see him wield Blutsauger.
No offense, but I have to agree with the people above: I can understand a few people hating on Yoshida, but when it gets to 5 or 10 people in a row saying they want her dead, it gets annoying. Keep in mind, I'm one who'd like to see Yoshida forget Yuuji and go with Ike, but...

THIS is what I'm starting to like about this series. Some really good drama going on all over. I was starting to think it'd be like Bleach but shorter (No, I'm not one of those "Shana is Bleach" people. Bleach just taught me I wasn't a fan of actiony series anymore.), but now it's becoming one of my favorites.