My Murphy Ancestors from Bog West, Mayglass, in County Wexford

Attached is a paper I've done, entitled 'My Direct Line of Murphy Ancestors: Focusing on Sources', which encapsulates the research I have done so far.  I have deliberately restricted my paper to my direct paternal line of ancestors, without distracting sibling details.

What I'm after is someone to constructively criticise the work I've done.  I have most likely erred in places and I am trying to find out where. I really need to know.  As they say, if you don't know what you don't know, you'll never find out.  I'm also seeking appropriate overall advice on how best I might further enhance my Murphy ancestor research.  

I feel, myself, that there are 1 or 2 possible weak links in my line of ancestors. I'll give you one example. To set the scene, Dennis Murphy (1812-1895), son of Philip Murphy (1787-1871) and Mary Lamport (1783-1850), migrated to Australia with his wife and children in 1854-1855.  I recently found that Philip's parents were Dennis Murphy (1766-1814) and Elizabeth ('Betty') Pendergrass (1766-1814). These parent names appear in Philip's baptism record in the Ireland Catholic Parish Registers 1655-1915 for the Wexford Parish, Diocese of Ferns.  The baptism and death of Dennis Murphy (1766-1814) occurred in Dublin - the baptism being on 11 November 1766 at St Andrews, Westland Row, Dublin and the death being at Thomas Street, Dublin, and burial at St Catherine's, Dublin, on 10 January 1814.  The parents and grandparents of Dennis Murphy (1766-1814) lived in Dublin and their baptisms and burials are recorded there in church registers. What troubles me is that Dennis Murphy (1766-1814) was born and died in Dublin yet his son (Philip Murphy (1787-1871)) was baptised during that period in County Wexford.  Does this cast irreconcilable doubt on his apparent parentage?  

I don't know whether the sort of assistance I need can be provided by an IrelandXO volunteer or whether I need to approach a professional genealogist for help and guidance.