Based on Razor-Qt licensing policies that I read, the author of Razor-Qt prefer LGPL over GPL.
How the merge of LXDE and Razor-Qt will affect the future of LXDE-Qt? Will it also prefer LGPL over GPL.
I suggest both developers should consider it earlier before everything get more complicated.
My opinion is to prefer LGPL over GPL for native LXDE-Qt Application (even PCManFM), as it will help wider acceptance for LXDE-Qt especially from corporate sponsorship that may interested with LXDE as an alternative DE for enterprise purpose (GPL doesn't very good in it) or from non-Linux operating system that avoid GPL as possible (e.g. FreeBSD or another BSD family).
Just for information, there are many notable projects which avoid or move from GPL in favor to more relaxed license : VLC, GEGL, ApacheOpenOffice, SDL, PySide, etc.