Daigo physically cannot keep his nose out of crime.

Anyway, for this Ace of Spades quest... would it work out if he did something like offer his service as a mediator? Like if he can negotiate a different punishment besides "getting your ass beat" between the two parties?

Daigo is kind of a "fighting crime from the inside" person, but he obviously has the insider knowledge that crime is eternal. So what he's actually after is more keeping the local crime scene chill and stable.