Best questions to ask potential Au pair via skype?

[FairyTrain]

We will be interviewing (via skkype) potential an au pairs in the next few days and wonder if anyone has some good questions to ask them to make sure that they will be right for us? We have found a few suitable applicants through Aupair world. Any help greatly appreciated as feel a bit clueless? TIA

One thing I've omitted to ask (and regretted not to have done) is:
Do you have any -even little- medical problems that might affect you (list as appropriate):
Picking up a baby
Back problems
Allergies to cats, food, etc.
sleep problems
Depression
Diabetes, etc.

I have had an au pair
who came and I quickly discovered that one had a physical disability she'd not considered telling me about. It meant that she couldn't put my 14 month old in / out of her high chair, the bath, etc.
When I registered another with our GP, she disclosed clinical depression. She had been on 4 types of medication and had only come off 6 weeks previous to arriving. I've no problem with employing someone with depression - but not someone who hadn't talked to me about it as it was still current and she was unstable. Her meds. had only recently finished.

Other questions are very personalised:
Are you happy to live in the countryside/ centre of the city?

I've found health issues to be a frequent problem (abnormally so for young 20 years olds I think) with au pairs so agree wholeheartedly about asking about this. Incidentially you don't necessarily get told even when you ask.
Also ask about smoking habits - virtually all au pairs claim to be non smokers on their profile so take that with a pinch of salt and ask again - including have they ever smoked and if so when did they give up. I recently interviewed a 'non smoking' au pair who when quizzed had 'given up' two weeks before.
Also, dietary requirements/restrictions and what foods do the like/not like.
Reasons for wanting to be an au pair and what they plan to do next
Education background
Family background and what parents/siblings do for a living

Others that might help you but less important:
Do they have any friends in UK already?
Do they know anyone who has been an au pair and have they talked to them about what the job involves?

If you need somebody to drive ask questions around this too:

Have they driven on the left?
How recently?
Have they driven with children in the car?
Are they happy to drive at night/in a city/in bad weather etc.

All good questions, thank you! I hadn't thought about health but so true...