Clauses and Gerund

#1 It was a long time since I had met her. (My version)

#2 It had been a long time since I had met her.

According to book both sentences are correct. But I didn't get how we can use perfect form "since + perfect".

#3 she says that when he will come is uncertain.

#4 when she arrives, she will tell us about the expedition.

Why can't we use "will" (when she will arives) in #4 as used in #3.

#5 Inspite of being a miser everyone likes to spend money on her.

A. Inspite of her being a miser everyone likes to spend money on her. (My version)

B. Although she is a miser everyone likes to spend money on her. (Book version)

Why my version is incorrect? Not sure but in my answer missrelated participle is corrected.

#6 She is not ...........(blame) for this episode.

For me there should be passive form " to be blamed". But book says "to blame" is only correct answer.

Thank you