Centering / Indenting a paragraph?

[Bric]

Hi, I'm new to this list and to lilypond

I just learned that I can do this:


\markup {
  \fill-line {
    \hspace #1
    \column {
      \line { This is my first verse  }
      \line { For Column 1 as a  supplemental }
      \line { Text blurb below the score }
      \line { This is when I don't }
      \line { Want to align multiple  }
      \line { Verses directly beneath the score staves }
    }
    \hspace #2

    \column {
      \line { This is my second verse  }
      \line { It is for Column 2 }
      \line { of the second  }
      \line { Blurb. }
      \line { Pretty cool and all is well  }
      \line { Wit these two columns }
    }
    \hspace #3

}

The above is rendered fine, with two columns well balanced.

the problem is:  How do I add a third paragraph, centered and indented?

If I add the following after the above...

\markup {
  \fill-line {
    \column  {
      \line { \italic { I want this  } }
      \line { \italic { Centered underneath } }
      \line { \italic { The above two verses } }
      \line { \italic { Apparently, that isn't easy! } }

    }
    \hspace #4
  }
}

it is left-justified, left-aligned.  How do I shift the paragraph?

Also, while we're on this topic:

(2) How do I add an empty line (forced newline, paragraphbreak, or some such),
in the above sets of lines?

(3) How can I add other things like solid horizontal line (rules), etc.., etc. ?

Thanks