Max RAM confusion

I need help to clerify following things. Please help me with as much technical details as you can.

1. If there are dual sockets for CPU, will each CPU have access to full RAM or just half of full capacity?

2. What exactly determines the max RAM size per DIMM module?

3. With dual or tripple memory channel mode - is the max RAM capacity divided by half or third?
If not why?

4. If the CPU address bus is 64 bits wide, how does dual(128 bits)/tripple(192 bits) memory channel mode work?

5. How does number of memory chips on a DIMM module work? Does different number for different module affect anything?

6. How multiple cores in a CPU work in terms of process and memory access?

7. Why FB-DIMM can offer max cpacity of RAM then registered or unbuffered DIMM module for the same number of DIMM slots in the same motherboard?

thanks for you time