Woods family, Carrigans, Co. Monaghan

I am seeking any information about David John Woods b.  23/01/1877 in Carrigans Co. Monaghan. His parents were William Woods and Emily Buchanan Woods. It appears that David had an unnamed sister b. 28.3.1870 in Glaslough, Co. Monaghan. Her parents were also William Woods and Emily Buchanan. 

The 1901 census shows a Sarah Jane Boyd M/S Woods residing in Harrington Street, Glasgow, with her husband Robert Clarke Boyd, their children, and a ‘boarder’ David Woods age 24. (Age 24 in 1901 gives the year of birth as 1877) Only a suggestion but David and Sarah may have been brother and sister. Sarah Jane married Robert Clarke Boyd in Glasgow in 1895.

The 1911 census has the same Boyd family (without David, although I have cause to believe he was still resident there) at 104 Gairbraid Ave, Glasgow, the same address where my dad was born illegitimally in 1909.

The death of Sarah Jane Boyd in 1960, in Glasgow, age 90, (year of birth 1870) reveals her parents as William Woods and Emily Woods, M/S Buchanan. (see above)  Further evidence that David and Sarah were brother and sister. 

My dad was born illegitimally at 104 Gairbraid Ave. Glasgow in January 1909,  and I know that a David Woods was his father.  (paternity found by decree of court). David left Glasgow in May 1911on the SS Athenia, sailed to Canada and disembarked in Montreal. He was never heard from again.

My dad was adopted by the Simpson family. 

However, I have David John Woods, a batchelor, who died 4/10/1912 in Ballanagall. Co. Monaghan, age 35 (Age 35 in 1912 gives year of birth as 1877)  Present at the time of death was a James Boyd. I have no further evidence and this David may be a red herring! 

What I don’t know:

Is the David John Woods b.1877 in Carrigans, Co. Monaghan, the same David John Woods that died in 1912 in Ballanagall, Co. Monaghan?

Is he the same David Woods that lived in Glasgow and left for Canada in 1911?

Is he the father of my father? 

Why would anybody travel to Canada in 1911 and return just over a year later? 

I have no idea as to David’s religion and have been unable to find a grave. 

I realise it’s quite a complicated set of names, dates and places but any help would be really appreciated.

Andy