I loves both episodes, were far better than the original attempt.The art and animation is also just spectacular, should I say as good as Gundam 00?
Also, the one with the gate was better described in this one, it really interests me. This explained why Ed and his teacher can use alchemy without transmutation circle. Allot of interesting stuff.
The fact that their only mom they loved is enough determination. You also have to consider that Ed lost part of his body and Al lost his entire body adRAB to this motivation. If you knew that you could revive your mom using alchemy...would it be enough for you to revive her?
Also, they have created a monster out of a person who they love the most, isn't that enough?