SK Ditta » The word, "Lord" seems to imply respect. If someone addressed a person as "Lord", such as a judge in courtroom, it would seem to imply respect.
Well, yes, "Lord" implies respect, but it was used to keep the Hebrews in remembrance of the sacred nature of their God. Everyone may know the judge's name is Harry, but no one would call him that in the courtroom. To maintain his demenor, even his closest friends would not address him by his name in the courtroom.
Venus » why should God choose a name the meaning of which no one is sure? Name should be self-explanatory, or else it is not a name.
All in good time. The Jews attempted to keep it sacred by restricting its use. No one knows who the restrictions were imposed by, but given ready mankind's nature to pollute that which is holy, it's likely they were imposed by heavenly messengers, themselves, as protocol (if one believes in such messengers).
There are those on this site, for example, who, because they were badly deceived by the merciless machinations of the manmade sect bearing Yaweh's name, seek reprisal by polluting the holy name in their posts. Others pollute it because they believe in nothing holy. But the key word is pollute. People use words to pollute, tear down and denigrate. Thus the Jews sought to protect that which they deemed as holy.
There are numerous meanings that have been attached to the holy name. "Unchanging One" or "He Who Amasses Armies" -- we may not know what it means, but after the great battle against Jerusalem in the last days, the prophets tell us that the name of God will "no longer" be polluted (see Ezekiel 39*, Zechariah 14**).
* So will I make my holy name known in the midst of my people Israel; and I will not let them pollute my holy name any more: and the heathen shall know that I am the Lord, the Holy One in Israel.
** And the Lord shall be king over all the earth: in that day shall there be one Lord, and his name one.