1. I would say that you are largely protected against HSV 2. Men shed virus mostly from the shaft of the penis. However, they can shed from other locations like the rectum so though you would be largely safe, I couldn’t say you would be 100% safe.
2. See question 1 for that answer
3. Yes, oral infection with HSV 2 would basically be a vaccination against getting it genitally. Once you have one type of HSV in one location, you are extremely unlikely to get it in a new location.
4. You don’t need to use a condom with masturbation, that’s not necessary if you have intact skin on your hands. The odds of transmission via masturbation are very close to zero. I wouldn’t worry about that particular risk. It takes some quantity of virus to infect another person and in the scenario you are describing, the risk is again, very very low.
If you do decide to have intercourse, it would be best if he was taking antiviral therapy daily, like valacylcovir or acyclovir as it reduces transmission by almost half over no medicine at all. Does he currently take medication?
You have two more questions to ask, please feel free.