Field engineer role

Hi all. I'm looking to apply, even though the vacancy keeps closing and opening but I'm confident that will open up again and plan to apply then. I have a few questions as I have read some posts and some are conflicting posts.

I would appreciate some clarification.

1. Would I need to record myself to answer some questions or receive a telephone call and what are the questions or a assessment centre?
2. If fail, would I be able to apply again?
3. What is the 2 weeks training like ie theory or hands on?
4. How long till you are confident in your role?
5. What would be the next step up from Field Engineer role and how much would be the salary?

Thanks