I have read here some tradition about laughing, it is blamed if one laughs too much or omits that it is bad. The believer’s laughter is his smile

But how do you understand such traditions exactly as they are meant or is everything to be considered in moderation because there are situations that are not haram and yet very funny.

I think your understanding is correct, that any behavior in extreme is not suitable. Thus, one shouldn’t be stern always or overly giddy