I have been researching my 6X Great Grandfather James McMichael. I have found his birth day 1727 or 1730 and died 1814 from Scotland. He married Agnes Barbour (Barber) in 1752
I cannot find any of the records you mention above on SP. What was the name of James father on the birth you found?
I did find the information on Agnes that you mention.
Patrick & Agnes married in Ayrshire.
BARBOUR PATRICK AGNES STIRRAT 09/08/1717 Beith
They had 5 Barbour children baptised in Beith and Agnes Barber in Dalry 13/06/1731, only father noted on all records.
Colin