Zephyros
Anubis777, I'm sure you know that the letters you are analyzing are of comparatively recent origin, not an earlier pictographic script. I read somewhere that if the story of Moses bringing the Tablets of the Law down from Mt. Sinai were literally true, the tablets surely would not have been written in the beautiful square letters with which we are familiar (although we may see the modern letters on the tablets in a certain Biblical movie).
http://exclaim.ca/images/The-Ten-Commandments-.jpg
The letters in that certain film are not the modern letters, but something I once knew, that film being my favorite, but forgot. They bear a certain resemblance to the Phoenician alphabet that while still inaccurate by perhaps a thousand years (although probably imaginary years) are still more true to form than the letters found in the Masoretic texts.
http://en.m.wikipedia.org/wiki/Phoenician_alphabet
I should think that if the actual formation of the letters is considered to have some sort of meaningful significance, perhaps it might be better to go back to the earliest known Hebrew script, if that is possible. Otherwise, we may be analyzing letters which, however beautiful, historically are not necessarily unique to the Hebrew language and certainly seem to have lost something of their earlier pictographic directness.
I once did a rather failed experiment with the lowercase letters, that do bear more resemblance to their definitions than the uppercase ones. Although it didn't work, it did yield an interesting look at their shapes.
http://tarotforum.net/showthread.php?t=189089
As to how they evolved and how big a deal is made, I think that like any field of the occult, those who study it usually seek to gain legitimacy by citing "ancient" texts and languages that "came from God," and Kabbalists were probably no exception. This isn't to deny their contributions, of course, but merging history and occult is to take myth at face value, a dangerous occupation, to my mind.
However, Anubis is on the right track, as far as that goes. The thinking, drawing of semantic conclusions, meditating why the Tower is connected to the Wheel (if at all) is the important part. Why things are what they are definitively is secondary in this case. More than anything, Kabbalah should teach one to think, but not what or how.