The 'you've committed crimes' dialogue would be optional, seeing as how bandit groups can be rather large and that would take a lot of time.
Guards would only be interested in arresting bandits and thief enemies any other hostile npc or creature would be killed as normal. Soldiers (imperial, Stormcloak, Thalmor) would be unaffected because they're not guards, they're supposed to fight and not ask questions. I feel like this would be a rather uncomplicated mod if it doesn't already exist. There's already bindings in vanilla gameplay and there's random encounters with soldiers transporting prisoners, but in game, guards just kill bandits. Is there a mod for guards actually arresting bandits and thieves instead of just murdering them to death? (And I don't mean taking advantage of them like a mod from a certain other website.) It's one thing for the player to ignore a yielding bandit, but guards should be arresting them. I can't seem to find an existing mod for this, but maybe someone can point me in the right direction.