In order to get my own thoughts sorted out, I am summarising what definite information is available about Norman Morrison.
From the index at
www.scotlandspeople.gov.ukThe marriage of Normand Morison to Isabel MacLenan was recorded in the Applecross parish register on 1 July 1813.
They had seven children whose baptisms were recorded in the Applecross parish register.
Ann, 13 July 1814
Janet, 20 July 1826
Abigail, 26 August 1820
Murdoch, 9 June 1823
Catherine, 26 March 1826
William, 26 March 1826
John, 22 June 1830
From the transcription at
www.freecen.org.uk, the family were living in Portlair, parish of Applecross, on 7 June 1841
Norman Morison, 50, agricultural labourer
Janet Morison, 25
William Morison, 10
John Morison, 7
Ishabella Maclennen, 55
all listed as born in the same county (whether it was the county of Ross and Cromarty, or merely the county of Ross, in 1841, is immaterial; the point is that
it was in the same county)
Adults' ages were supposed to be rounded down to the nearest 5 years in the 1841 census, so if their ages in the census had been accurate, this would imply that Norman was born between 8 June 1786 and 7 June 1791, and Isabella between 8 June 1781 and 7 June 1786. However the ages listed for Janet, William and John are clearly wrong if compared to their dates of baptism. If they were baptised within say three months of their births, then on the day of the 1841 census Janet would have been 23 and should have been recorded as 20, William would have been 15 and John would have been 10. Therefore you cannot rely on either Norman's or Isabella's age being accurate.
Now, Portlair. This is listed in Enumeration District 15 of the parish of Applecross. The other places in ED15 are A(i)rard and Diabaig. Diabaig is on the west end of the north side of Loch Torridon.
See
http://maps.nls.uk/geo/explore/#zoom=14&lat=57.5706&lon=-5.6867&layers=5&b=1 which shows all three places (you will have to zoom in and pan around).
http://www.geograph.org.uk/gridref/NG7960 http://www.geograph.org.uk/gridref/NG7959 and
http://www.geograph.org.uk/gridref/NG7958 which shows Araid/Araird/Airaird
Port Laire is marked on the present maps
http://www.geograph.org.uk/gridref/NG7957 and there is still a house there
http://www.geograph.org.uk/gridref/NG8057If you look carefully at the old map, you will see a double dotted line following the burn between the word 'Lower' and the word 'Diabaig'. This is the boundary between the parish of Applecross and the parish of Gairloch. Checking FreeCEN, several households in Diabag are indeed enumerated in ED1 of the parish of Gairloch.
So it is perfectly possible that Norman lived his entire life in the Diabaig area, being born in Applecross and dying in Gairloch, without ever moving more than a few miles from there, and the marriages in the parish of Gairloch could have taken place in Lower Diabaig, north of the burn/parish boundary.
Therefore I think that the family of Murdoch Morrison and Christian Mackay, all born in the county of Sutherland, are a complete red herring.