I can't find a Thomas Faragher 1780 but the birth date given coincides with the christening date of Thomas Faragher from Malew.
There was another child to Thomas and Isabella shown in IGI called Thomas Ch1818.
The son William Curphey Faragher was still with his father in 1861 and it looks like he married Ann Kaighin in Kirk Michael.
By 1881:-
William C. Faragher Joiner 47 Lezare
Ann 47 Michael
Anna M 17 Lezayre
Thomas C. 15
William H. 11
Robert A. 9
Amelia J. 7
Isabella A. 5
A child Francis W. died young.
If you search Brian Lawson's BMD's you may find:-
1. Anna M. married William Needham 1891
2. Robert A. married Frances Crowe in Kirk Michael 1898.
3. The burials of some.
There is a Thomas and a William both on board the Etruria arriving New York 1895 which may be the same.
Amelia J. married Henry Corner in Long Clawson Leicestershire 1902.
Isabella A is still in Lezayre in 1901.
Len Faragher