Something i thought about but I don't remember seeing anyone talk about (not that i checked all too much) is the Elrics return to the other world in order to destroy the gate was unnecessary.

Alphonse had the ability to remotely operate armor suits even through the gate (that being extremely comfortable for the plot and not having any consequences is another thing) so instead of the brothers leaving their original world, Al could have resolve that easily by sending suits of armor to destroy the gate, without the brothers leaving Amestris.

Don't get me wrong, i think Bones did a great job with the source material and created a great show, and the ending is quit fitting in emotion, but this part felt overlooked.

(Bare in mind it has been a long while since i watched anything from the 2003 anime so my memory of it is quite blurry, bu i remember thinking about it shortly after watching the movie)