Thank you for clarifying things, and for the innovative effort to improve Steemit! I have used Steemit since early 2017 and always found aspects of it confusing, unwieldy and/or in need of improvement. The video helped me to understand at least the 1st and 4th keys.
With that in mind, I would like to request:
A better editor. This basic editor offers nothing for novices, especially since many of the documents created 2 years ago about using HTML and MDL are now partially or entirely incorrect because they either suggested HTML that is no longer usable, or they suggest using styling features that the editor no longer possesses (which is everything). Using HTML and MDL can be hit or miss, and not just because of the conflicts between the two languages or the limited amount that can be used, but also due to the lack of documentation and links that users can click to learn how to format their work. I had to research and write several articles on editing here to help ME remember it all and help others. One article I wrote the other day, in which I made a list with MDL, had to be rewritten because of that conflict, forcing me to switch the entire, lengthy, list to the HTML ordered list tag, which has its own problems.
A 5th key that can be used for up/down-voting and resteeming but NOT posting and editing. The reasons for this SHOULD be obvious but, at the risk of seeming condescending, if someone gets your posting key because you gave it to a voting bloc, 3rd-party website or 3rd-party app, Malicious Owners have the power to not only down/upvote where you wouldn't agree, but to also create false posts, trash existing posts by changing the text, including spam and libeling people, which can result in the person whose posting key was abused to lose rep, be flagged and so on, which can have potentially long-term consequences. Worst of all, such deleterious actions could be done by a bot app, so the MalOwn wouldn't even break a sweat. Thus, the 5th key would be at the bottom of the hierarchy.
A way to delete messages (active key?).
A list of all available keywords or, better yet, a tree categorization system that will reduce unintentional overlap/duplicate categories (due to different spelling/ounctuation/words, such as golden-oldies/goldenoldies and food/cuisine). This has long been a problem for me, because the list shows popular keywords - not all of them - and many are related to cryptocurrency, which doesn't help those of us who don't write about that. This inadequacy in Steemit makes it very easy to associate your article with "dead" keywords that will not help you get an audience.
Tied with this should be a counter showing how many posts are in that category to help people avoid dead zones.
Finally, an option for curators to suggest categories for articles would allow people to help in SEO of writers' articles, with the authors making the choice of which keywords (aside from the main one) to use, and which to discard, which could increase their audience
System-wide announcements like the one I saw for this article. This is the FIRST Steemit-wide alert I've gotten since 2017. I honestly do NOT know where to look for updates from the people who control Steemit and the onus is on you guys to alert us to changes. Sure, we don't necessarily use best practices for security but, then, I didn't even know until relatively recently that there are now 4 keys!
A flag for plagiarism and a flag to show you don't own what you're posting (the latter prevents the former and also disables payment on upvotes). I have seen a lot of people earning money on here by ripping off someone else's work, including photos, and putting them on Steemit. That's like compilers on YouTube who take other people's clips and put them together into a large compilation of funny stuff, and then get rich off other people's clips. I find it to be unsavory at best.
If someone puts up someone else's work, they should either turn off payments or produce something substantial with the piece they grabbed being a supporting portion of the article or video instead of the whole focus, and also give credit to the source. If it is free-use material, they can still give credit if they want to support the creators, or not.
If you have any questions, please let me know! I hope you'll read this!