Is William Barclay a respected theologian in mainstream Christianity?

William Barclay A prolific author of 70 books, including commentaries on each New Testament books, is a well known and often quoted scholar. However some have written articles about him and challenge his Christianity based on the facts that he did not accept the miracles of Jesus, did not believe in the preexistence of Jesus, was a universalist and as can be seen in the quote below did not hold to classic views on the trinity. >Nowhere does the New Testament identify Jesus as God. Jesus did not say, "He who has seen me has seen God." He said, "He who has seen me has seen the Father." There are attributes of God I do not see in Jesus. I do not see God's omnipotence in Jesus, for there are things which Jesus did not know. I do not see God's omnipotence in Jesus for there are things which Jesus could not do (William Barclay, A Spiritual Biography, 1977 Edition, p. 56). Is William Barclay an esteemed scholar recognized by main stream Christianity, or are his views considered heretical in many ways?