Hi Michael,
There is a free transcription of the Guernsey 1841 census at
http://members.shaw.ca/jerseymaid/peterport9.html which has a Roderick MacKenzie age 25, schoolmaster at Hubits, District 9, St Peter Port. Others in the household are
Catherine MacKenzie age 50, born England
Eliza age 25, Ind born England
Jean, age 20, born England
Elizabeth, age 20 born England
Francis, age 10, born Guernsey
There is a marriage on FamilySearch at St Mildred, Canterbury 3rd Aug 1811 of Roderick MacKenzie and Catharine Kennett.
The middle name Murray and names like Colin, Donald and Jean in the family suggest a Scottish origin. I am wondering if Roderick's father was a military man, that would explain the Scottish surname being found in Kent and the family moving around.
Information about the Priaulx Library website and their research service information is at
http://www.priaulxlibrary.co.uk/I am afraid I don't know anything about burials and I don't know of any online marriage information.
Joy