A 200 mw laser should be able to hit a person from over 100 miles. That is of course if it has full battery
200 miles
Any light beam will go on forever, though it will become attenuated, if not absorbed by intervening matter.
As far as your eyes can see...
10 ft
A standard green laser pointer has a power of between 4 and 20 milliwatts. A red laser, for comparison, has a power of less than 5 milliwatts. The beam of a green laser can often be seen, while the beam of a red laser cannot be seen.
about 2 metres love
get laser goggles
do you mean how far does the light go? red lasers can reach up to 10ft (at least as far as I've seen). at 5mw green lasers can range from (3000ft - 5000ft and still see beam clearly). at 5mw
Some can travel over 25 miles.
The answer is pretty much "No." You can increase the power slightly, but if you go much beyond what it's designed for you'll burn out the laser diode.
200 miles
It should go on forever unless there's something in its way or the battery isn't full