Moving to Qatar with family - many questions/conce (Doha)

Hi everyone,
so I am from Germany and currently interviewing for a job in Doha – last round. Before potentially getting the offer and not having a lot of time to decide, I rather gather all information now already. So here I am having a few questions but staring with two ;)
-Living costs. We have two kids. One is going to school and one is still in kindergarten. We want to put them on an international school. I contacted the school already and it shouldn’t be a problem to get places. But what would be the living costs I have to budget for? I do get housing allowance and study allowonce. What should the overall package look like to have a decent live?
-My wife is scared about not being able to leave the country or getting into trouble. Internet is not always helpful ;) Any real concerns on that? I appreciate that something can happen always everywhere but are there “Qatar-specific” concerns?
-Any other advice/tipps we should look into before making the decision?
Living abroad is nothing new to us. We lived in South Africa nad my daughter was even born in London. So the “general living abroad” is not an issue for us. Also English is not a concern for our kids.
Thanks for any feedback.