TENSES

Here is a corrected exercise , but I think there are some mistakes
Let me know what you think please?

It is about a murder of a woman,her son is suspected. He is answering to the police.

i'll admit that I had been having(1) some problems but not more than any mother and son. the major problem had been(2) my ongoing relation with Susan. My mother did not like her. She thought(3) Susan was not good enough for me, we had argued(4) about her many times. The last time I saw her, we had had(5) an argument about Susan. We are going to be married next week and when I had asked(6) my mother to reconsider her decision not to come to the wedding .When I pleaded with her to come,she had refused (7).

I think there are mistakes in 4, 5,6,7 All these verbs could be in past simple there is no need for past perfect .It is very cl ear that all actions took place before the death