The 1841 census gives James Moir's age as 55. Adults' ages in 1841 were supposed to be rounded down to the nearest 5 years. So he could have been any age from 55 to 59.
The 1841 census was taken on 7 June so
if his age is accurate it means he was born between 8 June 1781 and 7 June 1786.
The 1851 census says he was 68. The 1851 census was taken on 30 March so
if his age is accurate he was born between 31 March 1782 and 30 March 1783.
The 1861 census says he was 76. The census was taken on 7 April so
if his age is accurate he was born between 8 April 1784 and 7 April 1785.
The 1851 and 1861 ages are clearly incompatible with one another, but either is compatible with his age in 1841.
In the transcription I am using (
https://freecen1.freecen.org.uk/cgi/search.pl) both the 1851 and 1861 say that he was born in Inverury. You should view the originals of these census at
www.scotlandspeople.gov.uk to satisfy yourself whether it reads Inverurie or Inverness. (And if it is Inverurie, use a better transcription in future
)
Noting that none of James' five sons was named Andrew does rather suggest that his father is not likely to have been Andrew. I see that Janet's parents were Alexander and Isabella, which is in line with the naming tradition, so I would expect James' parents to have been James and Janet.
Helen More married Jonathan Davie in Chapel of Garioch in 1817. In 1841 a Jonathan Davie, 64, was farming at Kirktown of Rayne. The only other Davie in the household is Catherine Davie. She is clearly too young to have been Helen's daughter. There is a marriage of Jonathan Davie to Catherine Milne in 1835 in Rayne. So it looks as if Helen More or Davie must have died before 1835.