1. Impromptu Take Away Interview Tips:

Remember, taking the job is your choice.
If you choose to go through with the stress interview, don't take it personally.
Asking for presentations or asking wild card questions are perfectly acceptable ways to add stress to the applicant without insulting them.

2. Impromptu Job Interviews Tips:

Look at from that perspective, something clearly sticks out – what about networking? What if you meet someone that owns a company or is in charge of hiring for a position in your personal or professional life, and you might be right for the role?

What if your friend introduces you to his boss at a dinner, and as your friend introduces you to their boss, they say aloud “So and so works as an X. We're hiring for an open position in the X department, aren't we?”

The boss looks at you, mentions that they are indeed hiring, and suddenly you find yourself in a job interview – an interview that you did not plan for. What do you do?

3. Tell me, I have a report in which i need to include a prompt of type Dropdown (Combo box) picklist including a particular column from data base. How to implement this type of prompt in Impromptu?

create that prompt in catalog itself , using the columns you want.

later in the report just equate it to the report column you want to filter on.