As far as I know, it's based on your in-game log in times, not the sub itself. A flag is set after 14 days of not logging in, and there's a delay for a day or two for the system to realize that you've recently logged on when you come back from hiatus.

The main /r/ffxiv subreddit is not the best place for a long post, because it's favors short memes with witty comebacks and threads have a relatively short lifespan. You'd be more successful posting a single line question with a cute picture and leave a link to a thread in the comments if you wanted to go that route, because most people won't have the attention span for it. But while you'd get a lot of feedback, I'm not sure how illuminating the responses would be. The /r/ffxivdiscussion subreddit would be where your thesis would make more sense, because there's a slower overall pace to the discussions and they prefer more in-depth, thoughtful answers. That's why it exists in the first place.

I don't think it's really about getting support for your ideas at this point. I think most people would find a change in direction to be refreshing. But I'd really like to see a proposed plan come together from the community. What are the issues holding healers back? What can be done next major patch? What can be done next expansion? If I put you in charge, how would you fix this mess, in broad strokes?