I've not tested this specific one, but the balloon tires you see nowadays (Schwalbe Big Ben/Big Apple or similar) provide a pretty good amount of suspension and

I've not tested this specific one, but the balloon tires you see nowadays (Schwalbe Big Ben/Big Apple or similar) provide a pretty good amount of suspension and handle well on rough surfaces. Small wheels will be an issue if you're dealing with potholes. Agility is not going to save you with a passenger, so don't rely on that in the first place.