Questions about Bit Rate Control

[DigitalVeil]

I've got a few questions about using and understanding bit rate control in ML.

1. What exactly does Qscale do? Is it the same thing as "slice control" from Tragic Lantern? Does it change any other parameters?
2. Does BR control in ML adjust the GOP value at all? Is it even possible to record All-I on cameras that are normally limited to IPB?
3. Regarding the bit rate info overlay, there are 4 boxes.  Obviously A and B are pretty easy to understand, but I don't understand the green box (has a variable percentage) or the red box (always says Q+-1).  Could someone explain to me what these 2 boxes refer to?
4. Just out of curiosity - why is CBR limited to 3.0? Is there a limitation with the hardware or the encoder? Or is this just for user-friendliness? I'd love to see what 300Mbps would look like on these cameras.