PQ2 Diagram

Hi everyone, 

I want to ask some questions about PQ2 Diagram. 

1. When the current setup is not in the safe region, will it affect the results? 
2. What is the difference between the maximum allowed solid fraction and the maximum allowed solid fraction constant? Why does the maximum allowed solid fraction constant has units of degree C?
3. What is Tnoflow? Whether h is a shot sleeve length? S is the total ingate area value, right?

Best Regards.