Thanks to all that responded so far! It is heart-warming to see overwhelming support in this forum.

About the family visa requirement (QAR 10K), can anyone confirmed whether this is based on the 'Basic Salary' or on the total gross (total package in the offer is QAR 13K)? The job offer did not indicate that the company will be applying for the Family Visa, although from our initial discussion, they mentioned that they are open on providing "assistance" for the family visas, and the offer did indicate that they will be covering the annual holiday air fares for my wife + 1 child once they are here (I assume that I will be shouldering the cost for their Manila-Doha air fares initially).

Regarding the school fees, I'm afraid I have missed that item altogether - will be bringing this up though soon.

The comments have brought about another question --- since I've only signed a job offer, will it be prudent to assume that I will be presented a "probationary" contract initially and then another contract later on?

If yes, I'm thinking of accepting the offer as-is, then later on negotiate to include your respective recommendations.