Appointments registration fields and confirmation

I would like to add a couple of fields to the registration when people apply for it.

Besides that most preferably I would like it to be confirmed only the first time and after that it should not be necessary anymore because then we now who they are. But the first time we need to meet them for instruction.

So there is in fact a couple of things I want to:

1 Add fields to the registrationform, like company, and a textfield

2 There needs to be a manual confirmation only the first time. After that they can register freely at any time with no confirmation.

Thanx so far,

Saskia