Well, I think the way to approach this is to establish the tone of the piece, and when something is happening that is in conflict with that tone, either do one of two things:
1: Revise the scene so that the things that the characters are doing or saying are more fitting for the tone of the scene. This may require retooling sections so that the sequence of events fits, or rethinking a character’s motivation so that it works better in the scene.
2: Lean into the tonal dissonance of the scene, show on the page how jarring or discordant the behaviour is from what the tone of the scene is. This may make the silly jokes at the funeral seem like anything from a poor attempt to hide grief behind bad humour, to a psychopathic inability to read a room. It depends on what effect you’re going for.
All of the situations listed in your question are moments of tension and conflict. Minor conflicts, perhaps, but they’re the kinds of situations that can give us great insight into characterisation and how the world of the story works.
What does it tell us about the person who just can’t stop making jokes at a funeral?
What do we learn about the relationships between the people at this party where this person has their outburst?
What do we learn about the person struggling’s (in)ability to cope with pressure?
Essentially, tone is yet another element with which we convey the central ‘meaning’ of the text. In what ways can these conflicts of tone help to illustrate the important threads of meaning and narrative within the scenes where these conflicts take place?
I hope this helps!