Quotes bolded wherever applicable. Qualified wherever necessary.

1)
It is far better to be on your own than with someone just for the sake of not being alone. That applies to friendships as wells as relationships.
2)
To proclaim my understanding and competence on a subject, and then change my mind on it because my understanding was shown to be incorrect, it’s embarrassing for me, especially in public, as I fear it makes me look stupid. I prefer to avoid this and usually wait until I am sure of my understanding and knowledge before I start talking about it.

Agree? Disagree? Neither? Etc --
I always couch my understanding and competence on any subject as "Subject to change with additional information". Always in terms of "as I understand it..." etc.

3)
I am naturally sceptical of second-hand information and whenever possible prefer to trust my own experience to reach a conclusion about something.

or

On the contrary, I think any one person’s experience – including mine – may be too narrow or limited, and I prefer to broaden it by getting as much second-hand information as I can.
Some combination of my own understanding and experience and synthesis of hearsay. I prefer pools of information that I can analyze for internal connectivity and common conclusion. Reliable and objective "sources" of information for fact-based assertions.

4)
If I need to learn something quickly, my first instinct is to ask someone I see as knowledgeable on the subject, rather than find my own way through it in books, the net, etc.

Agree? Disagree? Etc
I do my own research to gain a good thorough grasp of the main issues. I can generally come to a basic understanding pretty quickly.
5) level of sexual attractiveness (or lack thereof) in relation to others around me:

Hmm, no. I am never sure about such things.

Never really sure. It's kind of a blind spot.

6)
Especially in moments of crisis, I am inclined to be paralyzed by indecision and tend to wish, later, that I had acted more quickly.
7)
I worry about being awkward when dealing with people.
8)
It is a very common state of mind for me to feel that, whatever I have done with regards to a task, or when doing something for someone, I could have done just one bit more.
9)
I respect, even admire, people who don’t back off from confrontations, even physical ones, and who take physical risks (not necessarily at the level of some Jackass stunts, but I think you get the idea).
10)
I enjoy poetry and often write it myself.

Changed.