I have fn1 left as wifi, f2 for level gauge f3 for focus method (point, multi area etc,) , f4 histogram, f5 electronic shutter. Idon't use sofy fn buttons 6 and 7
I use C1 for my all general shooting, set to photo style std, aspect 4:3, quality RAW, meter auto whole screen (top icon), burst rate M (to keep image showing), self time 2sec, extended IISO on, face recognition, i everything off, af/ae lock - af lock only, hold on, evf/ monitor dispaly outside vf area, shoot without lens on ( to use manual macro).
C1 I set to aspect 16:9 large jpg for my Youtube vedeo stills and C3 Movie mode using AVCHD 720p (for Youtube)
I don't use C3 - 2 or 3.
I shoot only RAW for all my stills work.
Basically, with that C1 set up for my general work, if I want to make a change for a particular shot I do so on C1, knowing that when I switch off and then later back on, I know what all my settings are.
With those fn buttons set and the external buttons for af/ manual, iso, exposure override, and white balance and the 2 dials and thumb wheels, I have no need for the menu at all, giving me easier control than I ever had with my film cameras.
Don't get me started about the Lumix Link. I have done a series of tripod based macro shots today. Manual focus with that huge VF image on the iPad is fabulous. With the electronic shutter on and fired from the iPad screen there is no chance of any camera shake even on the 3 second exposures I've been using. Plus I can change the aperture, exposure override, almost everything.