So, am I being fake by subconsciously acting outgoing with everyone?

If it's subconsciously then I don't think I'd call it being fake. You're just subconsciously choosing to show yourself as outgoing, when you consciously think that you are not outgoing. This is probably a good thing but change it if you want.

I don't particularly like or have to have social interaction to be happy.

This is almost definitely not true. You may currently be getting a lot more social interaction than you need but chances are that you enjoy and even need some amount of social interaction. You just need to decide how much you want.

When out to lunch with other co-workers, people try to get me to talk, but most of the time I am stirring up other ideas in my head and do not wish to participate in small talk. This is the reason I prefer to take lunch hour in my office alone. It's just much more peaceful.

I go for walks on my lunch and avoid this too. But you should note that if you would like to have more stimulating conversations (on the ideas in your head) this can happen if you get more friendly with some of your co-workers.

Going to family gatherings, going out with friends, and sometimes even just going to see my parents is a royal pain. If I know that I have something to do on a Sunday night in one of the above categories, it stresses me out. It's not that I don't like to see these people, but I never feel extreme motivation to want to see them. Talking on the phone is usually good enough for me. Secondly, when I arrive at these places, unless there is alcohol involved, I usually am ready to leave within an hour or so. I have this need to go back home to be in my own house. Even the house in which I was born and raised doesn't provide comfort anymore.

This is very much the description of an introvert. Most people here will relate. Nothing wrong with this at all.

I don't view myself as any more intelligent than those around me. I just know a lot of stuff about a lot of different things. It's a hobby. I enjoy learning the ins and outs of a certain subject once I am set on learning about that subject. This just seems natural to me.

Me too (kinda). I love coming across people who have the same kind of questioning mind as mine. The amount of things I have looked up out of strange curiosity is staggering.