How can I query the node in XML with XQuery?

1. I store the xml info below in the XML field Demographics in SQL 2005, I hope to query all the node info with XQuery.

The result just like
<Folder Name="Root" Id="a6dce8fe-749c-4e38-ab2f-3d03d9711b3d">
<Folder Name="Card" Id="b8dcf8fe-749c-4e38-ab2f-6d03d9711b8j">
</Folder>
</Folder>

but I can't get the correct result using
select Demographics.query('/Folder') from store

2. Furthermore, How can I query the Name attribute of the Folder node by ID of Folder using XQuery,
If so, I can get the Name (such as "Root") after I know the ID "a6dce8fe-749c-4e38-ab2f-3d03d9711b3d"

3. Can I get the result below using XQuery? (Notice: the sub Name="Card" have no content )

<Folder Name="Root" Id="a6dce8fe-749c-4e38-ab2f-3d03d9711b3d">
<Bookmark>
<Title>CodeGuru Forums - ASP.NET</Title>
<Url>http://www.codeguru.com/</Url>
</Bookmark>
<Bookmark>
<Title>We will e-mail your press release</Title>
<Url>http://www.dpdirectory.com/</Url>
</Bookmark>

<Folder Name="Card" Id="b8dcf8fe-749c-4e38-ab2f-6d03d9711b8j">
</Folder>

</Folder>

Could you help me? Thanks!

=========================XML Info=====================================

<Folder Name="Root" Id="a6dce8fe-749c-4e38-ab2f-3d03d9711b3d">
<Bookmark>
<Title>CodeGuru Forums - ASP.NET</Title>
<Url>http://www.codeguru.com/</Url>
<Description>This is a good site</Description>
<InputDate> 2005-12-5</InputDate>
<IsPrivate>False</IsPrivate>
</Bookmark>
<Bookmark>
<Title>We will e-mail your press release</Title>
<Url>http://www.dpdirectory.com/</Url>
<Description>This is a good site</Description>
<InputDate> 2004-12-5</InputDate>
<IsPrivate>False</IsPrivate>
</Bookmark>
<Folder Name="Card" Id="b8dcf8fe-749c-4e38-ab2f-6d03d9711b8j">
<Bookmark>
<Title>Welcome to ePassporte</Title>
<Url>https://www.epassporte.com/</Url>
<Description>Very Good</Description>
<InputDate> 2004-08-5</InputDate>
<IsPrivate>True</IsPrivate>
</Bookmark>
<Bookmark>
<Title>Keystone DreamCard</Title>
<Url>https://www.mydreamcardonline.com</Url>
<Description>Please note</Description>
<InputDate> 2004-08-5</InputDate>
<IsPrivate>True</IsPrivate>
</Bookmark>
</Folder>
</Folder>

======================XML Info=====================================