Webclient Performance

I have a question about performance of the webclient component.
Currently we are using the Mozilla webclient to do parsing of a webpage
to generate the DOM.  We have two components, a designer and an engine.

This limits our options, because we need the visual representation of
the html webpage using Mozilla in the designer component.  But in the
engine we don't need to render the webpage.

Is there any way to turn off the rendering of the webpage in webclient,
since we don't need to display this, we are only utilizing the parsed
DOM.  This slows down the processing and is unnecessary overhead.

We have tried to set preferences to disable image loading, etc...

Is there possibly another setting to disable the rendering?  

Has anyone needed to do something similar?

Is there a way to improve performance of the parsing?

Also we are loading the file locally, not off the Internet.

Thanks

Alex