As convener he visited Kenya as part of the International Christian Federation Conference for the Prevention of Alcoholism and Drug Addiction, and also toured the Holy Land.

As convener he was responsible for the reports presented to Margaret Thatcher after her notorious Sermon on the Mound in 1988, which were interpreted as a rebuke to her speech.

He also served as chairman of the Lord’s Day Observance Society of Scotland (1970–1974) and moderator of the Presbyteries of Caithness (1964–1965), Falkirk (1983–1983) and the Synod of Forth (1985–1986).

Dr. McGhee made various television and radio appearances, often presenting "Late Call" on ITV, and was one of the most frequent speakers at the General Assemblies, taking a conservative, evangelical stance on theological issues.

A stained glass window of St. John was erected in his memory in St. Andrew’s West Church, and a new residential street built in 2005 in central Falkirk, McGhee Place, was named after him.