I'm autistic too; like you, I have difficulty reading people, and I've been caught out and/or taken advantage of plenty of times.
I think that's why I'm so interested in the almost subconscious, seemingly instinctive processing of interactions, behaviour and personality that the average person apparently has going on without even knowing they're doing it. To a large extent, I have to substitute for that function using the conscious, logical, slower, less nuanced, more cognitively--taxing type of thinking that would typically be used for problems that humans don't have a built-in system for. Like, I dunno, calculus or something.
But funnily enough, I've found that just occasionally, not having that subconscious, almost instinctive system for understanding other humans has allowed me to detect dodginess that goes unnoticed by most other people.
For example, I was once in a long-term psychotherapy group run by a highly-qualified psychotherapist with excellent social skills, who used all kinds of interpersonal, empathic skills and techniques to manipulate group members individually, and group dynamics as a whole. She seemed to be able to bypass people's defences with the way she talked, and, for example, could get them to come to particular conclusions they wouldn't normally have arrived at by themselves, or change the way they perceived or felt about other people.
But for me, this didn't work. The ways she was speaking, the things she was doing, were things I've had to learn to consciously notice and understand, and I could see that she was using them in an atypical way, in a relationship where they wouldn't usually happen. I could see that she was doing things that upset or soothed or distracted people by connecting with them in an instinctive empathic and emotional way that doesn't naturally happen for me, and that meant their brains didn't throw up the alarm signals that mine did when she spoke in non-sequiturs, made devious arguments, slipped in verbal sleight-of-hand, and — basically — slipped things under people's radar that, if they'd been written down in black and white in front of them and presented solely to their conscious minds, would've been more obvious for the self-serving manipulation they were.