Is this torque rating at the horn of the servo motor or the torque
rating of the actual motor before any gear reduction is done
For reputable manufactures and vendors, the ratings will include all internal gear reduction, or external in the case of gear-head motors.
Is this motor sufficiently strong for my application?
That depends more on the details of your application. 200 oz-in of torque means the servo should be able to lift up to 200 oz within one inch of its center shaft. That means it can work on up to [ 200 oz / 16 oz/lb ] = 12.5 pounds within that inch.
To get 4 - 5 pounds out of it, your rotational radius must be within:
12.5 lb-in / 4.5 lb = 2.78 inches.
However, operating the motor continuously under a full load will most likely cause it to fail fairly quickly. It will also slow down the rotational speed.
Speaking of speed, the servo is given at 0.23 seconds / 60 degrees. That means it will rotate 60 degrees in 0.23 seconds. a Full circle is 360 degrees, so 4 * 0.23 = 0.92 seconds for a full rotation.
However, (and correct me if I am wrong) no where in the listing does it mention continuous rotation. A traditional RC servo motor cannot rotate all the way around unless it specifically states it can or is manually altered (voiding any warranties). It will typically only rotate a maximum of 140 to 180 degrees.