Question Re: Force Constant Voltage - MSI Afterburner

[BigDay]

I'm overclocking an ASUS Radeon 7950 HD GPU with MSI Afterburner. When I run OCCT (my preferred stress test; with error check enabled), my core voltage (VDDC) measurement fails to go over 1.11V as shown in GPU-Z; I have my core voltage set to 1.2V in MSI Afterburner. The test ends up coming back with errors, which basically means the clock is unstable

 

Question #1:

 

Could it be unstable because the GPU is not receiving enough voltage?

 

Question #2:

 

If I enable "Force constant voltage" in MSI Afterburner, could this potentially solve this issue by feeding the GPU the volts I originally set (1.2V)?

 

Question #3:

 

Is it safe to run "Force constant voltage" on an overclock that's used for maybe half of the day at most OR a 24/7 overclock?

 

Question #4:

 

My core voltage (VDDC) measurement remains at 1.188V during idle (on desktop, surfing net, etc), but it goes down when I run a GPU intensive program like OCCT. Why doesn't it stay closer to 1.2V like I had originally set it?

 

Thanks!