My view is that, all four questions doesn't (and didn't) need to be closed.
The shape of letters, as well as pronunciation, is an interface between mental representation and physical reality, so that "misconception" happens here is clearly visible. What answerer should do isn't training the OP or correcting individual shapes one by one like, this letter good, that one no good, and so on, but pointing out where this "misconception" or "mismapping" lies, which I believe is not a difficult task for those knowledgeable about the language, at least intuitively.
Of course you could say that the OP should ask in more narrowed-down way, but I think showing all hiragana and all katakana is not only harmless but helpful to see overall tendencies (it's a valid question how you do this with kanji though). Note that, as I observe, they are not asking simple questions that textbook would tell you, but are likely to be too faithful to textbook or overgeneralizing it that result in their errors, so correction will help they learn how to write Japanese.
It's arguable that writing is not a part of language..., but practically we read and write in daily communication, in Japan and most other parts of the world, you know.
It may be still problematic that the question wording is always too vague or broad such as "good", "legible", "understandable" etc. I'd appreciate it very much if someone would think up more precise (or recommended) expressions that can indicate where they actually want to ask about. I can't imagine an average learner would form a question like "Are my characters well kerned?" or "Do my glyph X, Y, Z have enough counter?"