You're on the right track.
0000 0000 is usually your first address, so that would be your first bulb. Alternatively, you could rig it so that 0000 0000 turns everything on or off.
The speed depends on the weakest link which, in this case, would be the serial interface. At 9600 baud, you could issue 120 commands per second. You can go faster.
The RS-232 protocol is pretty solid: the odds of a communication problem are usually because of poor wiring. Note that the max cable length (spec) is 50 feet. If you run it longer, then the data rate drops (no signal integrity). I've seen 2400 baud over 1/4 mile of CAT3 cabling.
