I think Undyne-chan didnt get burned as a result of the Leydenfrost effect as the undyne is way too cold and Salamander-chan way too hot so nothing gets burned just the excess water.
Because ojiro was thinking about his dream and about how he doesn't deserve to have one and out of nowhere this woman talks to him, i have an inkling he wants to be a dad.
I mean it said anonymous thread it could go from 2-chan or 4-chan to a forum in the dark web since the protagonist does have illegal weaponry i think he uploaded in the dark web for whatever reason which is not safe.
Being yakuza doesn't mean killing people, the actual profitable part of being a yakuza is loan sharking and black market activities like drug trafficing, yakuza have been able to continue for so long because their gang war dont happen as often or are as showy as other gangstes.