...Also what happens to all these twins he has flying around? Do they create a softball team of clones? Like Joe Shmoe playing all 9 positions and managing versus the high school girl's softball team?
Well, I think they're not "clones" per se
, it's simply that they cease to exist in their own timeline as they go through the hole in the floor and enter a parallel universe's timeline where they probably already have a near-duplicate, but if the duplicate has already gone back in time (or is about to), then that's 2 of them out of their native timelines, and so on. The plot does not try to resolve what happens to all those duplicates crossing into other timelines, but I like the central theme picked by the movie, which is that one
of the duplicates has to cross over to many timelines and go back deep into the past in order to effect a positive incremental change in the "present".
I think that's a great SF story, and it reminds me of a quite different SF film, "Jacket" (which I thought was superb and have watched several times). "The Time Traveller's Wife" is another, similar, I guess.