Aldy started off firmly in Chaotic Good territory, but has been shoved towards the middle by many embittering experiences. I would say he is currently Neutral Good, dancing towards True Neutral if a few more crappy things happen to him.
Good/Evil Scale:
He means well and wants the best for everyone, but some people simply need to die horribly as an example to all those who would try to repeat their crimes. He does certainly have a ruthless streak now, taking no prisoners when it comes to those he considers irrevocably evil like Sani Sabik, Sansha, pirates and the sort. Killing for duty is able to be respected, but killing for personal gain, fun or the fulfillment of an illegitimate philosophy is nigh unforgivable. Better to just put the dogs down loudly and violently so the rest of the pack gets the message.
This ruthless bent would probably become a central part of him if he ever becomes evil. He is also paranoid about betrayal and might now sometimes push away some perfectly decent people if they have mixed loyalties, hang around scum, have a spotty past, or are otherwise questionable. Still, there is plenty of good left in him, you just have to clear off the layer of crusty bitterness that has formed over it in the last five years.
Lawful/Chaotic Scale:
Aldy started life as a capsuleer not really caring much about tradition, social status and the like. He came from a background that is about as free as you can get in the Empire (privately employed entertainer/artist/intellectual) and never really had to bow down much so long as he stayed likable to the right people. He could speak as a virtual equal to most Holders and could also easily move through the commoner and even slave castes without causing much of a fuss. Life was his oyster and rules were just there to make sure idiots didn't mess up.
Then he was an idiot and messed up. After the whole Izanami ordeal he realized that he needed to be humbled and to get some discipline in himself so that he would never fail his morals so thoroughly again. Thus Bitter Aldy was slowly developed through two years of self-inflicted pain through his training with Otheiran, trying to keep the Knighthood together, and fighting that unwinnable FW.
Now he has come to the conclusion that people are crap and rules exist to keep them from degenerating into disgusting, depraved animals. Nevertheless, not all rules are needed. He hovers near the lawful scale, but still breaks rules when it suits him.
Now! For all you lot:
Anslo: I'd actually say Chaotic Neutral. He certainly goes in the face of authority, but he is more shaky on the moral front. He seems to mean well, but he does have a spotty past and seems a little selfish at times.
Karmilla: Not sure what she has done most recently, but True Neutral with strong Chaotic leanings does seem to fit what I've seen of her. Is mean, but not completely crazy, respects Amarrian tradition somewhat but mostly does what suits her.
Steffanie: Certainly Lawful Good. Thing is she is trying to consciously follow that path, which may or may not work out.
Pieter: Lawful Neutral with Good leanings. Haven't seen him take much of a moral stand yet, but seems pretty decent and well-intentioned.
Makkal: True Neutral with Chaotic leanings. Hasn't taken any moral stances as far as I can tell, and clearly does not care much about the standard rules of conduct insofar as social interaction goes. She might respect her local laws, but she doesn't at all seem like the type to go out of her way to bend over backwards for them.
Merdy: Paladin all the way!
Silas: Evil Overlord all the way!
Saede: Chaotic Evil. Ho blew up my Coercer unprovoked! 3 to 1! When I was defending my homeland! Honorless scuuuuum!
Synthia: Lawful Neutral. Means well, but is Sabik. Can't be a good if you believe there are savants destined to rule over the rest of the wiggly worms of humanity.
Aria: Agreed.
Samira: Also agreed, and she'd better not go evil on my watch!