Great-Grandmother found in Derrindaffderg; Help with birth record and other questions

Thanks to the many of those of you who helped me research my great-grandmother's parents. Her name was Anne (Kerrigan) Lynch, 1866-1963. She immigrated to the United States in later part of the 19th Century and eventually married my great-grandfather, Daniel Lynch.

Recently, with the help of DNA connections and newly found cousins, I learned that her parents were John Kerrigan, of Partee, Mayo, 1815-1876 and Mary Finnerty about 1840-(?) of  Derrindaffderg, Mayo.

Now I have more questions and I hope you can help.

Anne Kerrigan's birth record is attached. She was born in Derrindaffderg, You'll see her name on the left hand column three quarters of the way down next to the date 23 Sep 1866. Three questions on this document

1. Is the date for birth or baptism?
2. The names Anthony Henaghan and Cicily Higgins listed below her name. Are they her Godparents?
3. On the right side of the page, there is a 2 and 6. What does that mean?

Another question where/and at what church were children from Derrindaffderg baptized in 1866? Or did the priest just visit certain areas and perform baptisms?

I looked at Griffiths Valuation for Derrindaffderg and saw that the record was printed in 1857. Is that the year that the townland was surveyed?

Finally, someone told me that the landlord for the townland was George Henry Moore of Moore House. But the attached details for the survey of the Finnerty plot shows the landowner as Malachy Touhy. Can you explain that?

Any other information about Derrindaffderg is appreciated.

Again thanks to all.