I don't want to add to the confusion, but I can relate what I know.My grandfather, James Fickes was born in Adams County PA in 1890.He said that he was Scottish/Irish, which is bolstered by the fact that he was a Presbyterian.He had a connection to a Valentin Fickes, and also to a Job(sp?) Fickes, from the early 1700's.I have been told that Fickeses first landed in Lewes DE about that time.The name, as far as I could gather is a combination of Celtic and Anglo/Saxon (A German variation is Fichte) and first showed up near what is now the England- Scotland border. More confusion: the current spelling may actually be Welsh.
There are Fickeses of various background/religions throughout the British Isles and Austrailia.
The name means "fate of death"of "son of executioner."
It seems that it may be a "catch-all" name when it comes to nationality.Much less common, of course, but along the same lines as "Miller" or "Myers/Meyers/Meiers" where families with the same surname come from different parts of the old world.