does this look correct?

> <xsl:if test="string-length(location)&gt;0">
> 	<p><b><xsl:value-of select="location"/></b>" - "
                                                        ^
The linefeed  and the space used for indentation on the next line
will appear in the output and produce a visible space in the browser.
The quotes will also appear in the output.
You should use xsl:text here (see below)

> 	<xsl:value-of select="publish_date"/>" - "</p>
The </p> end tag will end the block, i.e. you are getting
a new line in the browser.

Try
  <p>
    <xsl:if test="string-length(location)&gt;0">
      <b><xsl:value-of select="location"/></b>
      <xsl:text>-</xsl:text>
      <xsl:value-of select="publish_date"/>
      <xsl:text>-</xsl:text>
    </xsl:if>
    <xsl:if test="string-length(/gapinc/body_text)&gt;0">
      <xsl:apply-templates select="/gapinc/body_text"/>
    </xsl:if>
  </p>