The dude didn't do it. The "bandits did it". If bandits are dead, case solved. That's how he thinks he could get away with it. He's apparently done it enough times to be so bold with it you could assume the justice system is just as dumb as he is.
I did say they would start a war and blame the kingdom for letting it happen. I just doubt that they would be thorough past killing the bandits. I don't think this world is like the modern times with DNA testing and modern judicial system.
If she was intentionally disposed of that she would be found, there's nothing to do after that than exact revenge. So you find and execute the bandits. Maybe blame the kingdom for letting this happen and start a war. The guy is not going to be implicated even if the bandits manage to say a thing...
What makes the princess any different? A better investigation team? So they find the bandits, they execute the bandits. End of story. Who are gonna believe a bunch of bandits saying that they were hired by nobility?
It wasn't him who kidnapped the princesses, it was bandits - if you know what I mean.
His victims are most likely killed, but he could also just sell them off. If he disposes the bodies where they could be found, then no one has to be looking for them which risks himself getting investigated...
He did that while having the blessing from being related to the hero though. He kept his knowledge to do magic, but the extra output was unexpected because of the powerup.
It doesn't have to be an exact time, but inspections would have come at a schedule, so the merchant would have to leave before then. There can only be so many routes to take in a city, especially when the merchant is supposedly trying to sneak out dirty assets. Even then, the bandits' lackeys...
You haven't been looking then.
There's one about that innkeeper. The sex isn't always wanted - the women aren't always going to be pretty, and the women are always stronger.
There's also Valhalla Penis Mansion for something a bit less serious.