Hi Manuel,
What an invredible experience if you get the job. Life in Vanuatu is like stepping back in time, 30 - 40 years. We have been here almost 4 years, and there is absolutely no way we will ever leave. The advantages outweigh the disadvantageous 100%.
There is a French school and an English school here.
Malaria????? you didn't say where in Vanuatu you will be transported to, if it's Port Vila, there's no malaria. However, if you are going to some remote island then yes, there maybe malaria. Your wife would be very unfortunate to get dengue, it's currently the wet season here, and no one we know has got dengie. The closer you are to the sea, the less you will get mozzies.
Stop worrying about things that may not ever happen, come and enjoy paradise.