Mafia, at its core, is a game of logic skill (with a social cooperation aspect, but I'm ignoring that for this analysis). It is most frequently described as a game of deception, which is true to a certain extent, but that deception takes place primarily as a way affect the logical capacities of the other players, so we see that the true nature of the game is one of logic. There are two forms of logic that play a role. There is deductive logic, where players try to determine where contradictions exist, or use other methods to gain certainty about the identity of the mafia (or pr's). Then there is inductive logic, where players make guesses based on patterns of behavior. This is what is referred to as scumhunting. Inductive logic does not offer certainty, but it does enhance the chances of making correct decisions. For deductive logic, the role of town is to discover contradictions made by players, and to set traps that will generate contradictions. For mafia, the role of deductive logic is to usually avoid contradictions. For town, inductive logic should be used to provide targets for suspicion, and is used by mafia to create misdirection. Insofar as inductive logic is being used, the results should never be fully trusted, so always be at least slightly receptive to counter arguments. Not all "scumhunting" is based on logic. Shun that which is merely arbitrary, and avoid making beliefs about the way people behave based on small sample sizes. Always realize that perception of behavior is not absolute, and be willing to break your rules of scumminess if the situation is atypical.
I will use an informal understanding of odds when scumhunting. I will adopt a frequentist interpretation of odds, and as such, will not allow odds to replace other forms of perception. My strength is much greater in deductive reasoning than inductive reasoning (although my inductive skills are improving). If I am making a strong case based on deductive logic, it is a town tell. If I am copying someone else's case, and it is based on deduction, it is a null tell. If I am not contributing, then it is a null tell unless there is a strong deductive case to be made that I am ignoring, in which case it is a scumtell. If I back up someone, and I am using explicitly inductive reasons to do so, it is a very slight scumtell. Strong emotion will be a slight town tell from me, but treat it as a null tell, or I will start deliberately using it as a mafia tactic.
List of people I hate:
No one. If I ever seem mad at someone, it is only temporary.