No, Elder Fei was not killed by Wu Zhu. The person who killed Elder Fei could have been the Temple envoy because he was a robot and did not fear Elder Fei's poison. It could also have been a mistake when the Shadow was creating a serial murder case to assassinate the Qing Emperor. There were other possibilities, but it was certain that it was not Wu Zhu.

Yes, Wu Zhu had killed the Qing Emperor in the novel Celebrating Years. Wu Zhu single-handedly fought against the Imperial Army and guards and finally succeeded in charging in front of the Qing Emperor. The Qing Emperor and Wu Zhu fought. The Qing Emperor cut off Wu Zhu's legs and seriously injured him. However, the Qing Emperor was curious about Wu Zhu's true appearance and removed the black cloth covering Wu Zhu's eyes. In the end, he was killed by Wu Zhu's laser eyes. This plot was described in detail in the online novel "Celebrating Years".
The reason Wu Zhu killed Lin Gong was to help Fan Xian take revenge. Fan Xian wanted to kill Lin Gong, but because Lin Gong was Lin Wan 'er's brother, Fan Xian couldn't do anything to him. Thus, Wu Zhu decided to kill Lin Gong for Fan Xian. Lin Gong did not agree to his sister marrying Fan Xian. He thought Fan Xian was a sloppy person and was not suitable for his sister. For this reason, Lin Gong had always been dissatisfied with Fan Xian and opposed him in every way. In the end, Lin Gong sent people to assassinate Fan Xian. In the end, they did not kill Fan Xian. Instead, they killed Fan Xian's good friend, Teng Zijing. Fan Xian was angry at Wu Zhu for killing Lin Gong because Wu Zhu had made the decision for him without authorization. He had knocked Fan Xian out and killed Lin Gong himself. Fan Xian felt that this kind of arbitrary logic was unreasonable and also despised the existence of life. Wu Zhu thought this kind of killing logic was natural, but Fan Xian could not accept it. Fan Xian believed that Wu Zhu should not decide for him whether to kill his enemy. Therefore, Fan Xian was angry at Wu Zhu.
The reason Wu Zhu killed Lin Gong was to help Fan Xian take revenge. Fan Xian wanted to kill Lin Gong, but because Lin Gong was Lin Wan 'er's brother, Fan Xian couldn't do anything to him. Thus, Wu Zhu decided to kill Lin Gong for Fan Xian. Lin Gong did not agree to his sister marrying Fan Xian. He thought Fan Xian was a sloppy person and was not suitable for his sister. For this reason, Lin Gong had always been dissatisfied with Fan Xian and opposed him in every way. In the end, Lin Gong sent people to assassinate Fan Xian. In the end, they did not kill Fan Xian. Instead, they killed Fan Xian's good friend, Teng Zijing. Fan Xian was angry at Wu Zhu for killing Lin Gong because Wu Zhu had made the decision for him without authorization. He had knocked Fan Xian out and killed Lin Gong himself. Fan Xian felt that this kind of arbitrary logic was unreasonable and also despised the existence of life. Wu Zhu thought this kind of killing logic was natural, but Fan Xian could not accept it. Fan Xian believed that Wu Zhu should not decide for him whether to kill his enemy. Therefore, Fan Xian was angry at Wu Zhu.
The reason why Wu Zhu wanted to kill Fan Xian was to protect him. In Joy of Life, Fan Xian was threatened with an assassination, and Lin Gong was the mastermind behind the assassination. In order to protect Fan Xian and resolve the misunderstanding between them, Wu Zhu decided to help Fan Xian get rid of Lin Gong. In addition, Fan Xian liked Lin Wan 'er, and Lin Gong was Lin Wan' er's brother. If Fan Xian killed Lin Gong, his relationship with Lin Wan 'er would break. Wu Zhu didn't want to see Fan Xian and Lin Wan 'er separated, so he chose to personally kill Lin Gong to protect Fan Xian.
Yes, Wu Zhu killed Lin Gong. Lin Gong was killed by Uncle Wu Zhu. Lin Gong had been chasing Fan Xian and was Teng Zijing's murderer. Fan Xian knew what Lin Gong had done, but because he was Lin Wan 'er's brother, he had not done anything. However, Uncle Wu Zhu could not tolerate others hurting Fan Xian, so he personally killed Lin Gong.
The reason Wu Zhu killed Lin Gong was to help Fan Xian take revenge. Fan Xian wanted to kill Lin Gong, but because Lin Gong was Lin Wan 'er's brother, Fan Xian couldn't do anything to him. Thus, Wu Zhu decided to kill Lin Gong for Fan Xian. Lin Gong did not agree to his sister marrying Fan Xian. He thought Fan Xian was a sloppy person and was not suitable for his sister. The reason Wu Zhu had helped Fan Xian kill Lin Gong was to resolve the misunderstanding between Fan Xian and Lin Wan 'er. He wanted to protect Fan Xian and prevent their relationship from being affected.
The reason Wu Zhu killed Lin Gong was to help Fan Xian take revenge. Fan Xian wanted to kill Lin Gong, but because Lin Gong was Lin Wan 'er's brother, Fan Xian couldn't do anything to him. Thus, Wu Zhu decided to kill Lin Gong for Fan Xian. Lin Gong did not agree to his sister marrying Fan Xian. He thought Fan Xian was a sloppy person and was not suitable for his sister.
The reason Wu Zhu wanted to kill Fan Xian was because he had been reorganized by the leader of the Temple. His memories had been deleted and he no longer knew Fan Xian and listened to the orders of the leader of the Temple. Fan Xian was Ye Qingmei's son, and the Temple had ordered Wu Zhu to kill Fan Xian. Perhaps it was because the Qing Emperor did not want his illegitimate son to have a Great Grandmaster level figure by his side. He was worried that he would shake the stability of the country. In the end, Wu Zhu did not carry out the order to kill Fan Xian. Instead, he helped Fan Xian kill Lin Gong to resolve the misunderstanding between them. Fan Xian was angry about this because he had a compassionate heart. He believed that he should only take revenge on the people who assassinated him, not innocent people.