I only have a vague idea aboutthe first two of your questions: I guess they use the term silicon compiler as a description of an ideal state in chip synthesis s

I only have a vague idea aboutthe first two of your questions: I guess they use the term silicon compiler as a description of an ideal state in chip synthesis software where you can go from high level logic descriptions (VHDL source) to the final chip masks without any human intervention. Right now, this requires a lot of manual work in intermediate stages of the process. Being able to do away with that would simplify and speed up the process. But this also means tackling pretty nasty NP complete optimization problems.