1 I dont think they are, though PJ himself said that they were "recommendable for 8 years and older"
2 Could have been; but I doubt that most people would have liked it then.
It's great as it is as a film, and it's not LoTR, it's just an interpretation of it, and as such a briliant one.
There are already numerous threads about this opinion though -
http://www.killermovies.com/forums/showthread.php?s=&threadid=29857
http://www.killermovies.com/forums/showthread.php?s=&threadid=301533
http://www.killermovies.com/forums/showthread.php?s=&threadid=28401
http://www.killermovies.com/forums/showthread.php?s=&threadid=15349
http://www.killermovies.com/forums/showthread.php?s=&threadid=15296
http://www.killermovies.com/forums/showthread.php?s=&threadid=5456
Further
http://www.killermovies.com/forums/showthread.php?s=&threadid=10996
http://www.killermovies.com/forums/showthread.php?s=&threadid=22811
http://www.killermovies.com/forums/showthread.php?s=&threadid=13660
http://www.killermovies.com/forums/showthread.php?s=&threadid=13524
3 Good idea... would have been interesting; though I think it was a good choice (good for PJ ^^) to make LoTR first as it is simply the better material for a good film;
Few people would be interested in dwarves visiting elves who sing weird songs all the time
5