Mark,

I believe it was Kitplanes that said the #1 cause of engine failure with low time composite aircraft is debris in the fuel system.  I carefully wiped down my fuel tanks with a tack rag prior to closing and taped 4 ply breather patches over the vents with tape over the fuel caps.  After paint, I sloshed and drained the tanks several times.  With 400+ hours, I too still catch the occasional bits of glass/micro fuzz from the construction process in the Andair Gascolator.  A tiny strand or piece of debris that makes its way to the injector can be a problem. 

The best insurance against a engine fire is the best fuel hose/fitting you can buy.  This is supposed to be it.  http://www.aircraftspruce.com/catalog/appages/ae466.php 

Steve Colwell  Legacy