I'm still fairly new to BDSM and generally use this site to read and learn from but I the questions posed were very interesting and I do apologize for my long rambling replies.
I think it is entirely possible. Generally, it does seem that there are certain characteristics that many people who are dominate in relationships also carry in their every day life. They tend more confident, sometimes more dominating or take charge in their work-life then their peers. But I don't think that these apply to all. In my opinion, a Dom is someone who in relationship is able to inspire confidence and trust in a sub so he/she feels comfortable enough submitting and is a person who has enough confidence in himself to Dominant that individual. I don't think that just because someone is able to do this in a relationship means that they can necessarily replicate it in their everyday life with people whom they don't share the connection with. I do believe that by being a Dom in a relationship and having the ability to Dom helps develop the confidence and demeanor of the person but that development takes time and experience.
My initial answer is No. The only reason I can think of that would make a person who dominant in His/Her life be an asshole is if they were unable to compromise or consider other opinions because to be in charge they must always be right or if the way in which they present themselves is off putting because they see themselves as better then their peers.2. If you are dominant in all aspects of your life, are you automatically an asshole?
I do believe that Tojo is correct in that it is not appropriate to comment on the other thread. So, I will try to keep my answer general. Meeting your significant others parents can be an extremely difficult thing to do. I remember wanting to make the best impression on my Boyfriends parents when I first met them. It may have been because I lacked confidence but I tend to think it was more that I wanted them to like me. Maybe it is because I am still young, but parents of younger individuals still hold a deal of control over their child's life. If they don't like you for whatever reason: you drink, are immoral (in their eyes), too old, too poor, your corrupting their child, whatever it will become extremely difficult for you to continue to have a relationship with that individual and their parents dislike will effect the relationship.4. Is meeting the parents an example of a situation in which the Dom/me should be insecure? (I think that this, in comparison to other life complications, should be very simple.)
Being insecure in this situation is understandable, Wouldn't you be uneasy if you were in a relationship in which the parents of the individual you were dating, the parents who still control a great deal of their life, out right disliked or even hated you?