Hi David, and Welcome to Steemit.

You will find that Steemit is quite a different and unique medium. While there are plenty of crap posts, there is also a great variety of excellent, well-written posts on a wide (and increasingly wider) range of topics.

Given your broad range of interests, you'll certainly have plenty to bring to this platform. And clearly, you know how to write, and that is essential. Since Steemit is basically a blogging / publishing site, anyone who can write properly and clearly can do well. (I checked out your "Cannabis / DNA" post, and while I find most scientific writing incomprehensible, I must say that your text is quite readable and understandable.

Bring more just posts to Steemit, and you'll be on your way to a successful presence here. ☺

Below are a few basic points of advice re posting on Steemit.

1 – Longer posts are more lucrative than short posts. If you make a post of 20–30 paragraphs, it's more likely to earn rewards.
2 – Include some photos, images or graphs, to complement the text.
3 – Make sure the text and photos are formatted properly, so that your post looks attractive and appealing.
4 – Be yourself.
5 – Be interesting and informative.
6 – Create quality content. Steemit is intended to be a platform of quality content. (You will see many insignificant posts with meager content and no quality. Most of those of posts [called “shitposts” by Steemit whale Stellabelle] will earn few rewards and soon pass into oblivion.)
7 – Get online and start curating. Read various posts, comment on those posts you find interesting, and upvote those posts. That’s the best way to attract followers.

Hope this helps for now. Good luck, and Full Steem Ahead!