The advice given is too much... It unnecessarily add ups the fear of parents.
We are not going to face any war kind of situation. Its a simple interview. I say just they want to see the child and parents. Let them go freely and attend.
I can say school is not a matter. Your children can become a scientist by studying in an ordinary school. We have lots of examples lets take Honble Dr.Abdul Kalam, he came from some ordinary school.
Your children will become extraordinary. School is not a matter, it very much depends upon encouragement of parents and the childrens interest . Instead of giving so much donations you can buy a PC, books instruments etc.