Re: Martha Campbell and Samuel McClimon, Co Down, 1830
I search the IFHF's online database @ ROOTSIRELAND.IE. It has abt 19 million B/M/D and other records for MOST Irish counties. I also search the IRISHGENEALOGY.IE database. In both, records before 1863 are increasingly scarce. By 1800, they are almost non-existant. Many B/M/D events either weren't recorded, or the records haven't survived. Protestant records were the least likely to survive.
Mandatory (although often evaded) civil registration for protestants didn't begin until 1845.
For ALL the B/Ms you listed, I found 0 records.
You might query the Public Records Office for Northern Ireland: Google PRONI.IE to reach this office (fees apply).
Hope this helps. Good luck and happy new year.