>    many people in the gnu world are using qt4. are there reasons not to
   >    consider it?
   >
   > Two:
   >
   > * GNU policy is to use other GNU packages by preference, and QT isn't
   >  GNU.
   >
   > * GNU policy is to use C by preference to C++.

   Are these policies listed somewhere?

They are listed in the GNU Maintainer Guidelines, the GNU mainfesto,
and our project web page.