Well done Simon for taking the time to write an article. I've been meaning to do something as well and I wanted to give you some props for being confident enough to share your thoughts.
I think this article is very surface level. There's not much content of actual insight beyond "there are strong cards in dominion", "play with them", "go look up how to play with them elsewhere". You did list a few cards that you wanted to highlight, which is good. Perhaps you could directly link to some other articles or feedback that you found helpful at your level. Your opening section and replys have said that this style was your intention so I'm not going to critique this point further.
I think you could also add a section about "end-game play". It's one thing I have noticed on my climb through the 40s is that some players will practically give me the win with poor end-game play. If that's still something new to you, I would link to the
Penultimate Province rule. It's a lesson that really helped boost my rating, despite being an old article before Landmarks were released.
I'd also add a section describing the different styles of decks; engine, slog, combo etc. (I know these definitions have been fluid within the community). For your target audience, I think these are key lessons to learn and feed into your other points regarding Alt VPs, Landmarks and Events. With these concepts, it helps encourage the thought process of analysing the kingdom for which kind of game it will be, which I think is your key message.
Good Luck and Have Fun