Soak your head under the shower with warm water for a full 20 minutes. Time it if you have to. You wanna make sure it's a full 20. Then massage it off with your fingertips.
1. Yes
2. I don't believe so.
3. Depends on surgeon.
4. I wouldn't use it immediately postop.
Post some pics. Your donor area will dictate what you can do. It's also recommended to at least try propecia.
The amount of shock loss varies between patients. I'd say while you have a lot of shock loss, it's normal for having that many grafts and starting finasteride. I'd be confident that it'll grow back stronger.
Every patient has a different safe zone. A good fue surgeon will be able to extract the best grafts. Fue allows grafts to be taken from different areas other than the traditional strip area. Whether or not these are from the safe zone is debatable.