You asked me why I seem to have a habit of going over people's belief's over and over ad nauseum. I suppose it's a little bit of everything you suggested. The most basic answer is that philosophical conversations strike me as extremely important for one reason or another, so why fight it? :) Realistically, though, I think the most concrete and least non-verbal reason I have is finding out people's inner foundations for belief. All the specifics, whether you're Muslim or Christian or agnostic or atheist, are all just effects brought about by that foundation. I aim for the root.
And, when dealing with folks who have religious leanings, that root is almost always irrational or self-deceptive. What I appreciate in you is that you admit that it's irrational and probably not true, but at least it's fun in the meantime. I think that's healthy and entertaining. But what really gnaws at me is when people build up a shell around their irrational core and pretend that their beliefs are concrete and with a solid base. Every time I hear Yanniru defending the scriptures' many self contradictions by saying "That's God TRYING to mess us up" I feel like tearing my hair out. I have a ton of respect for the guy, but I hate it when people go through subconscious mental acrobatics to preserve their fragile shell of denial. So when I argue with people it's usually to try to break that shell to prove to them that they believe illogically, and it's likely that they're mistaken. Of course, it usually doesn't work, but I've had a few successes. (not on this forum) :) I am perpetually amazed by how often I see people denying evolution despite mountains of evidence to the contrary, defending a 6000 year old universe, saying that Adam and Eve were real people, the Flood really happened, and so forth. Those beliefs are destructive and self-deluding. So in short, irrational beliefs are fun as long as you admit they are irrational. If you wrap them up in a fog of mental defense mechanisms to pretend they're real, irrational beliefs are downright dangerous. (see: WTC)
In your case, you already admit that openly and have beliefs based on speculation and imagination. Cool. But I don't see your opinions as beliefs at all. A belief is saying "Though I don't have proof, I think this to be true." You say "Though I don't have proof, I think this might make sense as a possible solution." So I would say that you don't really have a belief-system, per se. Wouldn't a speculation-system make more sense?
I'll write more later, got to go to a neighbor's Cristmas dinner. I may not have any beliefs about the holiday, but at least I know that steak is delicious.