After looking at wikipedia and a few other sources, it seems to me the producers of that documentary may have been a bit too optimistic about He3, but it is difficult to judge a complex system like that. BTW, He3 does occur naturally in Earth, but the concentration is usually so low that production from most sources is inpractical.

There would be no effect on earth, and since the Moon is a barren body with no environmental worries, so in some respects that would make things simpler. Of course, the lack of breathable atmosphere and the distance more than makes up for the above. I

n any case, there should be no surprise that others (i.e. russians, chinese) are eyeing the Moon, too.