lol, I think you've got something approaching a good description here. In the first paragraph, I have pretty much the opposite tendencies that you do. I definitely do overthink things and wish I did it less, but it's almost automatic. Sure it helps me in the more abstract elements of my thinking (like the search of an over-arching meaning to my life, etc), but I certainly miss out on opportunities to do concrete things with it. Maybe it's because I perceive it to be so useful in many areas of my life that I have such a hard time cutting it out or not carrying it to the extreme.
Also, as different as we seem to be from the first paragraph, the second one sounds like a page right out of my book.