Lots of excellent advice already given, to which I can't add much.
This appears to assume that the main point of internal audit is to train auditees in practising for an external audit. It isn't. (OK, at times there may be that need, but it doesn't appear to apply here, nor was that my reading of what was asked.)
Disagree strongly with this:
:mg: Nope.
There should be quite a lot a difference between internal audits and external audits. I would never seek to model internal audit on external audit, nor advise it. That's to misunderstand the purpose, nature and function of each. It doesn't mean you can't learn stuff from good external auditors that you can apply in your own internal audits, but the two are different.
As Andy says:
Yes indeedy. Hit the nail on the head, Andy.
Erk. No, they won't. They'll almost certainly get the 'deer in the headlights' look and/or turn people off.
Look, I think I understand what you're trying to achieve with those questions and I can understand the goals and agree with them to some extent... but I disagree strongly with asking those questions in that way, as well as refuting your contention that there's no difference between internal and external audits.
Why would there be a difference between external and internal audits?
It's not the auditor's job to solve the companies problems. It's the auditor's job to ensure the QMS as adopted by the company complies with the standard, and that the QMS reflects reality on the production floor. IF the company is utilizing the QMS as intended, the nonconformities will surface. Then following the QMS, the company will resolve those issues, thus improving the quality of their process/product. The purpose of the audit is to ensure the company IS following the QMS, and the QMS follows the Standard.
Deer in the headlight look.

Happens every time you use ISO jargon. Ask open ended questions in a language they understand. What are you doing? gets them to open up, and ask me a question. Takes them off the defense. Yes the usual response is, what do you mean? To which I reply, tell me about your job.. Then we have a conversation, not a question and answer period. I steer the conversation based on my audit questions. If I'm looking for competency, then I ask qustions related to their skills. If I'm looking for non-conformity process, I ask questions about production errors, machine errors, etc. What happens to the part, do you put it on hold, how does that work, etc. They know their jobs, they know what they are doing. If they didnt know their job, they wouldn't be there long. The question the auditor must answer is this: does the QMS match what the employee is doing, and does the QMS comply with the Standard.
Yes an external auditor will ask more questions about the QMS in relation to the Standard, and yes an internal auditor will ask more questions related to procedures in relation to the QMS. However if the internal auditor isn't auditing the QMS to the standard, they will have findings every time.
At no point is the audit about employee performance. It's not the auditors job to evaluate the employee.