Con Kennedy research conundrum

I am a novice to Irish family history research.  My husband is descendant from Con/Cornelius Kennedy who immigrated to Australia in 1854. Con was the son of Roger/Rody Kennedy and Mary Maher who married in 1824 in the Parish of Borrisoleigh. The marriage register includes the townland names for bride and groom, Castle Hill and Knockaneevan (sp?) respectively ( https://registers.nli.ie/registers/vtls000632667#page/161/mode/1up ). 

Five of their children have been identified in the Borrisoleigh baptism registers: Margaret b.1825, Biddy (Bridget) b.1827, Con. (Cornelius) b.1830, Mary b.1832 and John b.1833. Different townland names are recorded in the baptismal register for each of the children: Castle Hill, Killomoyne, Knockacillan, Ileigh and Currabeha, respectively. I have presumed these to be places of residence at the time of baptism. Con’s baptism record can be viewed at https://registers.nli.ie/registers/vtls000632668#page/32/mode/1up

Antipodean descendants of Roger Kennedy & Mary Maher who visited Ireland in 2000 made a visit to the Tipperary Family History Centre and were advised that Roger’s parents were Thomas Kennedy & Mary Kilmartin (Guilmartin) of Knockacullin (Parish of Newport).

In 2001, my husband received a copy of his Kennedy family tree and it is only now that we are retired and have a trip to Ireland on our radar, that we are delving a bit deeper. We have several of Brian Patrick Kennedy’s books which are a good point of reference and we plan to attend the forthcoming annual Kennedy gathering in Rearcross. We wish to have a better understanding of which family members remained in Ireland and have been pouring over the registers & various records.

There are gaps in the Newport registers from about 1804-1812, however we have been able to trace eight children to Thos. Kennedy & Maria Kilmartin (including Rody b.1801) in the registers that are now available online.

We can now also trace one of Rody’s younger brothers, Denis and his family, through to a son, Thomas and his family who were resident in Knockacullin in both the 1901 & 1911 censuses. We can follow the naming conventions (more or less) with Denis’ family, and also with Rody’s sons’ families, however the naming conventions are blown out of the water with Rody’s own family which makes me question whether the Rody Kennedy who married Mary Maher in Borrisoleigh is the son of Thos. Kennedy & Mary Kilmartin of Knockacullin.

I have come across so many Kennedys & ors. with the same names that I am only just now beginning to question this further.

1. In Rody and Mary’s marriage record, the townland for Rody is noted as Knockaneevan (this townland is in Borrisoleigh parish). If Rody is from Knockacullin why is Knockaneevan recorded, unless this is an error. 
2. The first born son to Rody & Mary is Con/Cornelius, not Thomas and the second born son is John. Should we be looking for a Rody Kennedy whose father is Con/Cornelius from Knockaneevin? 
3. If Rody & Mary were resident in Knockacullin in 1830 when Con/Cornelius was baptised why is the baptism recorded in the Borrisoleigh register when Knockacullin is in the Newport parish? If Knockacullin relates to Rody’s place of birth, what is the significance of the other four townland names for his siblings? 

If anyone can help to explain the above, we would be most appreciative. All links to the various registers can be provided, as required for details. Many thanks, Peggy