Yes! I didn’t realize I misspoke and said が when I was referring instead to だ in this case. Thank you for being patient with me as we cleared that up.
You said
both nouns and な-adjectives need ‘だ ’ to ‘exist’ (花 ‘flower’, 花だ ‘is-flower’, again as per CD).
Since you know both Dolly-先生 and Rubin-先生, I will ask another question. I was watching these videos, and Dolly-先生 argues two things: Firstly, that some uses of で are the Te-form of だ, and secondly, that both で and な are deformations of the coupula だ. In your experience, is this good advice?
I have loved beginning my journey with Bunpro, and really enjoy that it links diverse resources. But Cure Dolly was the first grammar resource I found in Japanese that “clicked” with me, and I am trying to make sure I am not being overly dedicaded to them, since I know there is a lot of controversy about their methodologies,. I am a full time high school foreign language teacher IRL, so a lot of this is not new to me, but Japanese is definitely unique in many ways.