I think this is the only anime in which I actually like the main character! It's a wonderful series, one that really has me hooked. (I've been watching the Japanese version, which is probably a lot bloodier and more iffy, so my review will be a little off.) The show is on in the middle of the night, so there's really no reason little children would watch. The show's perfectly fine for 13+.
The series touches on religion a lot in the Japanese version. A man kills other people frequently because he believes it's "God's will," and believes himself to be God's messenger. The main enemies are named after the Seven Deadly Sins (Envy, Lust, Gluttony, etc). The main characters, Edward and Alphonse, are aetheists (as with all the other alchemists), and they openly admit it and wear their aetheism as a badge of pride. Believers in God are ridiculed a lot. In this series, God really doesn't exist. (Again, reduce the religious themes by half and you'll probably have the English version.) Violence is the same as every other anime: punching, shooting, mild blood, etc. As with other animes, morality is questioned and twisted a lot, and there really isn't a line between good actions and evil actions. Plus, one character (rightfully named Gluttony), is a cannibel and one third of what comes out of his mouth is "Can I eat him/her/them?" After asking, he usually proceeds to eat him/her/them after recieving stares from his teammates. (It's always just implied though, the most it shows is somewhat bloody remains of who Gluttony ate. Its not as bad as it sounds.) There's also mild swearing. That pretty much covers all the profanity. Honestly, anyone who watches Bleach or Death Note should watch this. It's very good!