Structured XML Generation using SQL

Ok, so I've never needed to use the new XML functions in DB2.

Until now. I've got a need for a data export that seems like it might be a
good fit for XML...

Basically, I need to dump invoice header & detail. But for each detail
line, there will be an additional sub query or two to provide some extra
info.

Example (manually created so pardon syntax errors)

<Invoice number="12345" date='2016-01-01'>
<line number="1">
<sku>456789</sku>
<upc>12345678901</upc>
<qty>12</qty>
<more_info>
<line>abcd</line>
<line>efgc</line>
</more_info>
</line>
<legal1>invoice legal verbiage 1</legal1>
<legal2>invoice legal verbiage 2</legal2>
</Invoice>

I suppose I could just use a set of .CSV files with "foreign keys" but
using XML would allow me to keep everything together.

So my questions to the experts:
Does this seem like a reasonable use of XML? Or am I asking for trouble?

Do you have links to good references for learning to use the XML
functionality in DB2 for i? I've looked at the SQL reference, and while
useful, I'd like something a bit more together and with more advanced
examples of putting it all together.

Lastly, once I build the XML...how do I get it saved into a text file the
IFS?

Thanks!
Charles