Upvote! Love your idea, I've been thinking of creating some kind of topics' list myself. I do most of the time just write what comes to my mind - except for a series I am writing in German about languages and some special (and sometimes funny) aspects. Further topics for this series are always written into my bullet journal (actually a plain notebook I am carrying around everywhere I am), it's my brainstorming book.
I have not decided yet how to keep on writing here, but creating a post with topics and plans is definitely worth thinking about. It surely helps get a good overview and get a clearer vision of what you want to provide your audience with.
Nice inspiration, as usual ;)
Cheers,
Ines