Yes, you can change the templates to produce RSS any way you like. I have a full-html version I use to replicate my blog into a web forum, and I'll post that here as soon as I have a moment.

Here's my full-html RSS template (hope this posts okay in the comments...)

<?xml version="1.0" encoding="<$MTPublishCharset$>"?>
<rss version="2.0"
xmlns:dc="http://purl.org/dc/elements/1.1/"
xmlns:sy="http://purl.org/rss/1.0/modules/syndication/"
xmlns:admin="http://webns.net/mvcb/"
xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#">

<channel>
<title><$MTBlogName remove_html="1" encode_xml="1"$></title>
<link><$MTBlogURL$></link>
<description><$MTBlogDescription remove_html="1" encode_xml="1"$></description>
<dc:language>en-us</dc:language>
<dc:creator><MTEntries lastn="1"><$MTEntryAuthorEmail$></MTEntries></dc:creator>
<dc:date><MTEntries lastn="1"><$MTEntryDate format="%Y-%m-%dT%H:%M:%S"$><$MTBlogTimezone$></MTEntries></dc:date>
<admin:generatorAgent rdf:resource="http://www.movabletype.org/?v=<$MTVersion$>" />
<sy:updatePeriod>hourly</sy:updatePeriod>
<sy:updateFrequency>1</sy:updateFrequency>
<sy:updateBase>2000-01-01T12:00+00:00</sy:updateBase>

<MTEntries lastn="175" offset="6">
<item>
<title><$MTEntryTitle remove_html="1" encode_xml="1"$></title>
<link><$MTEntryLink encode_xml="1"$></link>
<description><$MTEntryBody encode_xml="1" convert_breaks="0"$></description>
<guid isPermaLink="false"><$MTEntryID$>@<$MTBlogURL$></guid>
<dc:subject><$MTEntryCategory remove_html="1" encode_xml="1"$></dc:subject>
<dc:date><$MTEntryDate format="%Y-%m-%dT%H:%M:%S"$><$MTBlogTimezone$></dc:date>
</item>
</MTEntries>

</channel>
</rss>

Hmm. You'll want to change this line:

<MTEntries lastn="175" offset="6">

To something more like:

<MTEntries lastn="10">

I had it that way for a specific reason, and forgot to change it back.