The only thing that bugs me is - they never explained how exactly Amon could remove people's bending. Was it some sort of chi blocking? Spiritbending? Amon blocking off part of the brain that has to do with bending? If it was just chi blocking then I would think somebody would be able to just undo it, and I don't really see how someone who isn't the Avatar can spiritbend.
All Tarrlok said was basically"Idk how he does it but I guess it has something to do with bloodbending...". And of course during the flashback he mentioned that the Avatar was the most powerful bender because he could take away bending. So that established his motive but not really how he can do it.
I mean Tarrlok couldn't take away bending, neither could Yakone, and they were both bloodbenders. Katara knows how to bloodbend (even though she won't) and she couldn't figure out how to undo the bending block. So that leaves me wondering if only waterbenders can remove people's bending, or if it's something other benders could learn.
Maybe something to explore in Season 2.