The whole "Sin" thing annoys me to no end - both for what you mentioned about how it's pronounced, but also the further justification is that oh he's got a brother who abbreviates his name to "Rick" so that's taken and can't be used. But we can have at least three different Nickys, that's fine.

Then again this is the same woman who pronounces "Doyle" as "Dole" and "noir" as "noor" so of course she's going to mangle Cynric.