In answer to both questions, no, but both are issues we are aware of and have some ideas to improve on (I'm talking sometime in the future for this though).
iText no longer does a redirect. This is in CVS now and will be a part of 2.0.1.
how about allow to specify Content-Disposition as an attachement rather than hardcoded inline?
"inline; filename=\"" + documentData.getFileName() + "\"");
This is in CVS and will also be in 2.0.1.
<p:document disposition="attachment" ... />