Okay, but a small carrier can also do reconaisance and immediatly prepare an attack force once a target is found. Or can defened itself better against an incomming air strike.
It would have to be a really small aircraft carrier to fit under the treaty restrictions. It would still be more expensive to operate and more logistically demanding. The range of a PBY is about 50% greater than the range of a TBF.
This is true. With a tender, a unit of seaplanes or flying boats can operate from practically anywhere there is enough water to float them. This can plug any holes in a navy's reconnaisance net until such time as a proper airfield can be built.