You brought up an interesting point, neuroticism might appear and manifest differently in the various types. Like for instance, a neurotic INTP might appear sullen, depressed, extremely pessimistic and sometimes just plain weird, like my friend who I think is an INTP, I like him really, but he's an emotional mess and is sometimes overly paranoid, that is what makes me(also INTP) so different from him even though we share alot of other personality traits in common, I'm generally calm and untroubled most of the time(and I might appear more "normal" than him), so I look at him like

. I have my problems too and I'm kind of cynical but I try to deal with my problems in a rational manner, I've learned some coping mechanisms. I try not to worry about things or circumstances outside of my control, I think about it like a logic problem, look at all my options, choose to best option for the situation, and consider worrying about uncontrollable variables/conditions as "irrational"

. And really, I have a neutral mood temperament and it is difficult for me to experience any emotion in any high intensity(especially for an long period), this probably makes me very boring.
I think a highly neurotic ESFP or ENFP might be more obvious than a neurotic INTP or ISTP as introverts tend to interalize their problems more. I'd imagine a neurotic ENFP to be very high-strung, moody, impatient, wild, implusive, in fact, this describes my sister quite well(she is an ENFP). When me and her were growing up she would be very moody, bossy, and snappy, this used to cause alot of fist fights between me and her(and I didn't give a damn if she was a girl). I even questioned her type until I learned ENFPs have Te as a function, as she can be very selfish, bossy, and confrontational, I think she might be in a Ne Te loop. It's like she has some of the negative traits associated with ETJs without the more positive ones. She has calmed down and mellowed out somewhat the older she's gotten and we get along better now.
And I don't know if most INTPs suffer from social anxiety(this seems to falsey be associate with introverts in general), but some others(like me

) might not give a damn

. Some on the internet even seem quite proud of their social outcast/nonconformist status.