holy trinity sunday year b - isaiah

Isaiah 6:1-8
In the year that King Uzziah died,
     I saw the Sovereign sitting on a throne,
          high and lofty;
          and the hem of Their robe filled the temple.
     ²Seraphs were in attendance above God;
          each had six wings:
               with two they covered their faces,
               and with two they covered their feet,
               and with two they flew.
          ³And one called to another and said:
               “Holy, holy, holy is the God of hosts;
                    the whole earth is full of God's glory.”
     ⁴The pivots on the thresholds shook at the voices of those who called,
          and the house filled with smoke.

⁵And I said:
     “Woe is me!
          I am lost,
               for I am a man of unclean lips,
               and I live among a people of unclean lips;
                    yet my eyes have seen the Sovereign,
                         the God of hosts!”
⁶Then one of the seraphs flew to me,
     holding a live coal that had been taken from the altar with a pair of tongs.
          ⁷The seraph touched my mouth with it and said:
               “Now that this has touched your lips,
                    your guilt has departed
                    and your sin is blotted out.”
⁸Then I heard the voice of God saying,
     “Whom shall I send,
          and who will go for us?”
And I said,
     “Here am I;
          send me!”

Queeries for the text:
Why is God so frequently high and lofty?
What was the robe made of?
What do they mean by "feet"?
If 7 is the holy number, why do they have 6 wings?
Why is the God of Peace also the God of "hosts"?
Did the incense get a bit out of hand?
What does it mean to be unclean?
How does fire purify?
Who is "us"?
How can we say, "Here am I; send me!" to God today? 
 
What are your queeries?