She thinks she's all that.

Okay thanks 

I'm not quite sure what you are saying.

Your message seems to be;

すずみやハルヒ also seems to be a slut. Why was everyone surprised?

どして --> どうして?=Why? (am I correct?)

What I know about this anime is the voice actress of すずやハルヒ is 平野綾.

I don't know if すずみやハルヒ is a slut or not. Also, I am not sure if everyone was surprised (by what? by the scandal?). I guess people who are her funs would have been surprised. But regular Japanese people won't care about it because she is not super famous.

I think she is (rather was) cute but I'm also one of the regular Japanese.

けどハルヒすずみやもslutみたいどして皆さんはびっくりしたですか？

First, let me make sure of what you wanted to say. I guess it was like; Why does everyone call 平野綾 a slut? Does anybody know about it? どうしてみんな平野さんをslutと呼んでいますか。(どなたかそのことについて) 知<し>っていますか？

平野綾, voice actress, right?

Well, her scandal photo came out (probably many years ago in a paparazzi magazine). With a guy in bed.

I remember about it.