I was lurking on your reading thread and this looks like it might be a more appropriate place to offer some totally unsolicited advice
You can use the hash symbol to more quickly indicate headers - so #, ## and ### give you h1, h2 and h3 just by typing them at the start of a line:
## header 2
If people do use the spoiler tag, you can reply to their post, click ‘quote whole post’, and then you can copy and paste their text directly. Obviously that’s a pain, but thought it might be helpful to know.
If people want to hide spoilers without using the spoiler tag, I’d recommend using the drop-down “details” tag, like so:
[details=“spoilers!”]
write spoilers here
[/details]
Also I saw somebody mentioning furigana - you can use <ruby><rb>kanji here</rb><rt>furigana here</rt></ruby>, but there’s also a script that lets you do it less painfully.