I hadn't even seen where this thread finally went until just now.
Excessive and paranoid? Not on your life. I've Survived numerous toxic and extremely damaging encounters with both malignant narcissists and diagnosed sociopaths. Once, I was one of the people that routinely would tell people (even new acquaintances) that I was a "trusting" individual at the outset, and blah, blah, blah. I gave away entirely too much personal information about myself, including past history, financial woes, and so forth.
The whole gist of this post was to generate interest in healthy, personal boundaries. :D