If a player owns a world but has no forces (Space or Ground, I move a fleet in do I now become the owner and get the Development value added to my Production total?
Nope. You need to invade it. You can only capture empty *unowned* systems with fleets. See 4.41.
Since you need to do an invasion to take the system, which takes a non-survey fleet, you need a scan marker on it to jump to it.
To do the invasion, it will either need to be in your Comm range or you must invade it with drop troops.