Although I would like to NSFW content in my timeline, I think its better to have them blurred by default and only visible if I click on it. And any such post from NSFW subreddits should also be blurred by default. Saying this because I noticed a post from a NSFW subreddit in the front-page and it was displayed without any blurring. I can anticipate this leading to potentially awkward situation otherwise, especially when browsing the site during a slow day at work.
To add more; we can even add comment tags so that we don't have to use things like "/s" and instead have a clear thingy that says [Sarcasm], even if it sounds silly, people already use tone indicators so this just simplifies the whole thing. No relation to NSFW but similar.
I know Reddit the hive mind usually hates emojis but I think a lot of the tone indicators you wish for could be solved by people using them more commonly.
Having been though stuff like l33t speak where everyone was T3h ep1c H4x0r, emojis really aren't that bad as long as your post doesn't become a hieroglyph. Even then, it's just a different spin on what people have been doing since the internet was a thing