It appears to me (i had to read this in a hurry, short on time right now) that you are correct. I was trying to simplify things for the OP.
I tend to agree with you that in the three physical dimensions (excluding time as the 4th, of course) it makes sense the universe is spherical. I also agree that a cumulative effect of the universe expansion may have some effect on the exact time it took light to reach us. This subject is cutting edge science and we probably won't have a really good grasp of the total situation for some time.
It's a lot of fun to think about though.
TheRedneck
