If anyone has the chance, are these OK?

1.    Hande Yener informed Sila that she (i.e. Hande) has now reached second place.

Hande Yener Sıla´ya bildirdi. Hande Yener ikinci sırada oldu.

2.    Sila was very disappointed about this.

Sıla bunun hakkında çok hayal kırıklığına uğradı.

3.    Sila wrote her back an E-Mail that was less than polite.

Sıla kaba bir e-posta ona geri yazdı.

Just wondering, why is Sıla bunun hakkında çok hayal kırıklığına uğradı an incorrect sentence - or is it just not too good?

Hakkında doesn´t quite fit the context here. It is used more in the sense of "related to", "regarding", "with regard to" etc.

çok hayal kırıklığı doesn´t sound too odd. However, hayal kırıklığı is a noun and it means disappointment. Since you can´t say very disappointment, çok here functions as an adverb, and modifies the verb uğradı. So, "Çok hayal kırıklığına uğradı." actually means "She was/has been disappointed a lot. (many times)"

On the other hand, you can describe the extent of the disappointment with an adjective like büyük.

Büyük hayal kırıklığına uğradı= She faced a big disappointment (Literal translation) i.e. She was very disappointed.

Again, this is something that even native speakers do not pay attention to and they might make the same mistake while speaking. No problem if you say it that way, everybody will understand.

Wow, thank you.