What socionics type would theoretically fit this?

[SGF]

This:

Description: Nothing escapes the notice of the men and women who have Vigilant personality style. These individuals posses an exceptional awareness of their environment. Call them Survivors. Their sensory antennae, continuously scanning the people and situations around them, alert them immediately to what is awry, out of place, dissonant, or dangerous, especially in their dealings with other people. Vigilant types have a special kind of hearing. They are immediately aware of the mixed messages, the hidden motivations, the evasions, and the subtlest distortions of the truth that elude or delude less gifted observers. With such a focus, Vigilant individuals naturally assume the roles of social critic, watchdog, ombudsman, and crusader in their private or our public domain, ready to spring upon the improprieties -- especially the abuses of power -- that poison human affairs.

Autonomy. Vigilant-style individuals possess a resilient independence. They keep their own counsel, they require no outside reassurance or advice, they make decisions easily, and they can take care of themselves.
Caution. They are careful in their dealings with others, preferring to size up a person before entering into a relationship.
Perceptiveness. They are good listeners, with an ear for subtlety, tone, and multiple levels of communication.
Self-defense. Individuals with Vigilant style are feisty and do not hesitate to stand up for themselves, especially when they are under attack.
Alertness to criticism. They take criticism very seriously, without becoming intimidated.
Fidelity. They place a high premium on fidelity and loyalty. They work hard to earn it, and they never take it for granted.

[SGF]

Makes me think of ILI-NI 5w6 in certain aspects, IEI in others. But nothing quite fits.

Its mostly something counter-phobic type 6 does and sixes are "a bundle of contradictions" mainly due to how reactive the core motivation makes them.
Sometimes its like being a walking talking BS detector. I have this habit of reading people, especially body language & motivations.. but its more like something that happens subconsciously on my end aka I can't help but be this way.
Practice makes perfect I guess and Ive been involuntarily doing this since I can remember.

Autonomy. Vigilant-style individuals possess a resilient independence. They keep their own counsel, they require no outside reassurance or advice, they make decisions easily, and they can take care of themselves.
Caution. They are careful in their dealings with others, preferring to size up a person before entering into a relationship.
Perceptiveness. They are good listeners, with an ear for subtlety, tone, and multiple levels of communication.
Self-defense. Individuals with Vigilant style are feisty and do not hesitate to stand up for themselves, especially when they are under attack.
Alertness to criticism. They take criticism very seriously, without becoming intimidated.
Fidelity. They place a high premium on fidelity and loyalty. They work hard to earn it, and they never take it for granted.

The above quote is stereotypical for me :/.. fits like a glove.

e_e I guess one can say its a kind of paranoia..

[Hot Scalding Gayser]

Reminds me of a few LSI guys that I know. But I don't think it can only apply to that type or anything.

Also reminds me of a SLI man I know too now that I think about it. The caution watchdog crap points to Ixxx , "makes decisions easily" probably points to xxTx

[SGF]

I was thinking about e6 but this portion runs counter to it:

Vigilant-style individuals possess a resilient independence. They keep their own counsel, they require no outside reassurance or advice, they make decisions easily, and they can take care of themselves.

This sounds much more 5-ish. 6s are usually searching for some sort of external authority (be it a a thing, person, ideology, philosophy, etc) to help ground them until they learn to trust their own authority... integration into 9. 6s are a bonding type and tend to be more reactive/responsive to outside influences from how I understand it.

5s are also vigilant in the sense that they don't want to be overwhelmed by outside influences so they stockpile information to prepare and detach.

Nonetheless, the passage sounds very "head triad".

that seems more like it refers to other people and not systems of thought. A CP 6 can still rely on some system of thought while disregarding other people's input to avoid depending on them or simply due to trust issues.

At any rate I seem to be more ILE-Ti than any other socionics type and I do this as well.