At first, Aya's evil colour scheme seems needlessly stereotypical. However, think about: what does she want? The anihilation of all emotion and life or at least that's what she claims. Who in the comics Green Lantern universe wants that? Add in the fact that she's powered by the Anti-Monitor. That's right, Aya is the first Black Lantern (or Black entity).
In "Heir Apparent", it's easy to suspect Ragnar's plan to inherit a Green Lantern Ring had gone wrong when Kilowog's ring doesn't produce a uniform for him.
Though certainly jerkish, the Guardians' reaction to Aya in season 2 makes sense in light of the Manhunters. The last time they made AIs capable of independent thought, an entire sector was eradicated. Their new one developing a personality would be cause for concern.
And after what has transpired in "Cold Fury," it seems they were right to worry.
The Guardians going straight for the presumably lethal method of studying Aya (dissection) instead of observing her under strictly controlled circumstances seems needlessly extreme and destructive, even with their fear of a repeat of the Manhunters. Especially as Aya appeared to be unlike them; when she outgrew her programming as a navcomp, she developed a conscience and emotions, the opposite of what the Manhunters did. Then we find out that the Science Director created her as an experiment in making an AI with emotions, and when past!Aya got too curious and discovered the Science Director's secrets, SD wiped her memory, sealed away her emotions, and hid her in the Interceptor. As Aya managed to unseal her emotions, and the Science Director was apparently in charge of studying Aya, it makes sense that she'd jump straight to dissecting her; she's trying to eliminate Aya to protect her own secrets.
When Razer fights a Manhunter for the first time, he completely annihilates it in under 30 seconds. The Red Lanterns were formed in response to the Manhunters.
Why does Razer carry a bunch of knives and shuriken with him? Because they're Razer-sharp.
Razer can go for months without food, lives in a desert where food is scarce but heat is abundant, and was so good at making traps that he was in charge of them throughout his entire sector. Since those are all traits of cold-blooded creatures like reptiles, no wonder Razer hates getting angry.