1.a - Anaconda does indeed have its own set of packages/libraries, so yes, there is a lot of duplication. But this does ensure Anaconda had exactly the libraries it needs. For the Mac, it actually is our recommended method of installing PyFerret.
But, note that "miniconda" is what you want. Andy reported his difficulty in handling the full-fledged Anacoda.
For my successful story in installing pyferret using miniconda, please search the Ferret email archive. I list all the commands. It's just six commands or so before you get a working pyferret. I use 10.14.4, too. (Note, however, the same email thread includes my initial failure.)
Unfortunately that document doesn't include how to install miniconda or how you need to set PATH to include miniconda. I guess that's where Andy's initial difficulty was.
Cheers,
Ryo