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 --
It's a little embarrassing, but it's just part of the learning process, I think. Also I generally tend to blurt things out before they're fully formed anyway, so if I had to wait until I was sure, I'd pretty much rarely ever say anything of value.

3) 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.
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 ultimately like to look things up myself, although it's nice to have someone knowledgeable nearby to bounce things off of once I think I understand something to make sure I'm not out in the deep end. This may just be due to my personal learning style, which is that I seem to be able to learn things much better on my own than when other people try to teach me (unless they're just right on my wavelength).

5) I have a very good idea about my level of sexual attractiveness (or lack thereof) in relation to others around me.

or

Hmm, no. I am never sure about such things.
More the latter, although judging from the number of women lining up to bat their eyes at me everywhere I go, I have an educated guess.

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 far more about appearing stupid and/or ignorant among others than I worry about being awkward when dealing with people.

or

On the contrary, I don’t worry too much about appearing stupid/and or ignorant – I am more likely to worry if I am being boring, inconvenient, rude etc when dealing with others, collectively or individually.
I worry a bit about both, actually.

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.
^Usually. Occasionally, if I'm tired, I'll settle for something, but I usually know in the back of my mind that it could be better.

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).

or

Sometimes I may even wish I was better in such things, but normally I think that those who take physical risks (or risk getting into physical confrontations) easily are just being silly.
More the latter, but mainly I don't really care either way, as long as no one is making me get involved.

10) I enjoy poetry and often wish I could write it myself.

or

Poetry may be nice and all, but it’s ultimately pointless – I prefer writings that actually communicate something in a more straightforward language.
Meh, neutral.