Hillel's Famous Dictum

In yesterday's column, Neil Steinberg offhandedly quoted the Talmudic sage Hillel saying "the rest is commentary."

The full story (loose translation) is as follows:
A non-Jew approached Hillel and said that he would convert if Hillel could explain the entire Torah to him while he (the non-Jew) stood on one foot. Hillel responded and said, "That which you dislike, do not do to your friend. The rest is commentary. Go learn [it]."

Appartently, the potential convert was trying to understand the essence of Judaism. Or possibly, he was looking for an uncomplicated religion, one which revolved around a central principle. He had approached Shammai before approaching Hillel, but Shammai pushed him off.

Rashi has two interpretations of Hillel's dictum "That which you dislike, do not do to your friend." The first interpretation is that the "friend" refers to God (HaShem). Hillel is therefore saying: Do not transgress God's will, just as you would not appreciate it if someone else did that which you don't like. Now, you must go learn what God's will is - as described in the rest of the Torah.

Rashi's second interpretation is more in keeping with how I think most people interpret this saying: Do not do things which other people dislike, just as you wouldn't want them to do thing which you dislike. I.e. love your neighbor as yourself.

Two apparent difficulties with the second interpretation are:
1. why didn't Hillel simply quote the famous verse of "love thy neighbor etc"?
2. if this is the essence of the Torah, how do we understand all the commandments which are between man and God such as keeping the Sabbath and not praying to idols or other gods?

These questions may be what motivated Rashi's first interpretation.

Nonetheless, we can attempt to answer these questions:
1. Perhaps Hillel was indeed quoting the famous verse. However, since the non-Jew did not understand Hebrew, Hillel was paraphasing it in the common language - Aramaic .
2. Perhaps the essence of the Torah is indeed to produce a healthy society where individuals only do that which is pleasing and benefits his fellow. However, that is only possible if individuals understand that all people were created by God, in His image (b'tzelem Elokim). Therefore, HaShem gave us instructions (commandments) on how we can internalize that fact by serving Him in many different ways.