Hi honney,
It depends where country will you apply. Here in Norway, i submitted my application in London Visa Office. I didn't experience any problem though, it prolongs the processing because of lack of supporting documents. The time frame is only 8-10 weeks accourding to CIC London website.
Interview is allbout my duties and responsibilities in my current work, about my employer and they want to hear my english when talking.
less than 5 minutes
I found my employer through aupair website, i just make a lot of profiles then the employer contacted me through email.
I hope this helps