CTRL-Q does nothing when in Fullscreen - it shold quit the program, but is ignored.
Sean Davis referenced this bugreport in commit 69f31052223f24b4227072b4352c045aedc3f55f Support Ctrl-Q in fullscreen (bug #13549) https://git.xfce.org/apps/parole/commit?id=69f31052223f24b4227072b4352c045aedc3f55f
Thanks for the bug report. Resolved in the above commit.