Gerald, It is quite possible that the families are linked.I agree the names are too close not to be, eventhough there are some spelling differences.Most of the information I have on the website comes from individuals who have shared data with me and I simply linked them as the researcher suggested.
The Catawba River Valley begins in Burke County and continues through Mecklenburg on its was southward to the Atlantic.There are a number of counties that it touches or comes close to and where Canipe/Kanipe/Kneip/Knipe names were found.This also includes Mitchell County (migration ?); Cleveland, Lincoln, Gaston, Catawba, Mecklenburg, Alexander, Iredell...also includes the Rowan site where the first Kneips came after the Revolutionary War (Salisbury)
Name cahnges in spelling were pretty much as your uncle suggests--just a personal preference.My suposition is that the earliest census takers were somewhat illiterate and did not know the German spelling of Kneip (2nd vowel is pronounced as a long soound) and just changed it.This is why it got the English spelling at one stage of teh census of Knipe and later got the Canipe and the Kanipe...that seems to be the progression of spellings.
As you may know later Kneips did immigrate to the US -- one was governor of SD in the 70s, I believe.There is a Kniep office building in Pierre the capital.
I am working on some more material which I hope to soon get on the website at http://www.geocities.com/canipeplace/http://www.geocities.com/canipeplace/ Fore example I have a copy of the original land deed that Christian purchased when they moved to Lincoln County in 1795.I plan to scan that in and get it up.