I'm trying to create a name for a character of Noldorin descent, but I have no idea how such a name would work grammatically, just in general. Does Noldorin behave like Sindarin, with lenition and other mutations, or is it closer to Quenya?
Also, is there any chance of someone creating an English to Noldorin dictionary to complement the Noldorin to English one?
Far over the Misty Mountains cold, to dungeons deep and caverns old. We must away ere break of day, to claim our long forgotten gold.
I would say you can use Sindarin for a Noldorin character in any case. The Noldor themselves Sindarized their names, or received Sindarized or Sindarin names, or took names in Sindarin form of course.
Not that you didn't know that already
As far as I know, outside of the "Noldorin" of the Etymologies (in the superseded scenario illustrated there)...
... Noldorin is a term used by some to refer to an internal dialect of Sindarin, a dialect influenced by the Noldor and Quenya...