These are what we call the 'YMMV items.' Things that some people find in this work. We call them 'your mileage might vary' because not everyone sees these things in the same way. This starts discussions in the trope lists, a thing we don't want. Please use the discussion page if you'd like to discuss any of these items.
Award Snub: A lot of people felt that James McAvoy should've been nominated for his strong supporting performance. Of course, this overlooks that Nicholas is arguably the lead role despite Billing Displacement, Nicholas being the protagonist and in nearly every scene, and Amin the villain who is in the film much less. It did help that Forest Whitaker acknowledged him in basically every single acceptance speech he made (which was a lot).
Complete Monster: Idi Amin is a brutal dictator that takes what he wants by force. While he first comes off as a charismatic and modernizing leader to Garrigan, Amin brutally represses the population of Uganda throughout the film. Although he claims to be doing it to establish peace, his orders to deport people solely based on their ancestry (people from southern Asia) and murders based purely on suspicion show that he's fuelled purely by his paranoia. He deliberately cuts off one of his wives and disowns the son that she bore him simply because the child was epileptic. Amin later tortures Garrigan brutally with meat hooks after discovering Garrigan's affair with the previously mentioned wife and fully intends to torture Garrigan to death.
Jerkass Woobie: Nicholas. He's perpetually selfish and conceited. He doesn't seem to care much for neither of the married women he's interested in, beyond fulfilling his lust. However, finding out that one of your best friends is a mass-murdering dictator isn't decent karma. Also, watching him get tortured is brutal.
Moral Event Horizon: Kay's murder. You can almost see any illusions that Nicholas might have still had about Amin being completely shattered, and this is what finally pushes him into doing Stone's dubious bidding.
They Wasted a Perfectly Good Character: Idi Amin is of course the main selling point of the movie, and he pervades everything that happens in Uganda, but he's not actually in the movie all that much. It's not unheard of for audience members to get a little impatient with the Garrigan scenes (good though McAvoy is).