Thanks - we will add it to the list. Honestly we are always looking for more hotkeys, and ones that don't conflict with other apps are kind of hard to find!
You can make the screen more warm during the day using the "daytime" slider.
However, staying the same really is not what we're trying to do with f.lux. We think lights should change from day to night, it's the signal our bodies and eyes need to tell day from night.
I have been looking for such an option, thinking there was. However I was unable to find it. However - I just found it to be under the "disable" menu instead of general preferences. Thank you so much.