1. NP does not move for a given aircraft design. It is independent of CG.

2. NP is also independent of the horizontal stab design. Unless you are VERY sensitive to flight nuances, you will not notice a difference in stab design.

3. You are always safe forward of the NP. How close you can get without becoming unstable in pitch, I have no experience. You can also be safe behind NP, BUT it will get very risky if you miss by a small amount. Many full scales fly with CG behind NP.

4. This is for others to answer.

Have fun!

Bedford