"Tauney" could also be easily taken for a diminutive of "Antaunette" -- which is just one of the many of modern variations in spelling of "Antoinette
In the U.K., "Taffy" is a mildly derogative word for a Welshman.
I personally like your name for three reasons:
#1 "Tauney" has 6 letters, which qualifies it as a Satanic name.
#2 "Antaunette" is a feminine form of "Anton
", and Anton
LaVey was the founder of the Church of Satan.
#3 The meaning that you gave for your name is also quite appropriate for a Satanist. Even the "sweetness" part, coz Satanists can be sweet, too. ;)
I dunno if you're still going to like your name as much after all that, but *I* like you name. :)