Re: attributes and elements

                <content>
--->                    <xsl:if test="*/condition">
--->                        <xsl:apply-templates/>
--->                    </xsl:if>

The test test, whether one of the child elements of the
section element has a condicion element as child.
I just can't quite match the XSLT with your problem spec,
as a rather wild guess I'd say try:
  ...
    <content>
      <xsl:apply-templates mode="filter-condition"/>
    ...

  <xsl:template match="*[@condition='screen']"
     mode="filter-condition">
     <xsl:apply-templates/>
  </xsl:template>