The first sentence sounds correct. In the second sentence, I think it's better to use the verb "regard" since the verb "acknowledge" is usually used in contexts where you accept someone's authority over people, so "We always regard him as the best football player in the team." sounds more natural. In the third sentence, the meaning will be conveyed clearly if you use the present perfect tense correctly as in "hasn't accounted for". Thus, the correct sentence will be "After doing a lot of terrible things, he hasn't accounted for his mistakes so far."