Most of the time I use /s or :^) to highlight a contradiction between utterance and meaning*. Never for caustic speech; if it needs to be marked, it's pointless.

Not a big fan of tilde. I use it for a bunch of stuff already, like approximation (20 = around 20; 2030 = some quantity between 20 and 30) and drawn out speech (longcat is long~). The later is a weabooism, I know.

I'd be fine with any of those new graphemes in the text, if they caught on.