yea they review prior and make a assessment so the interview would be to corroborate the application info and it’s likely something didn’t correlate possibly with the answers also a big proponent is the length of the relationship etc - embassies approve and deny visas every day for decades and decades, the process is more algorithmic with computers today rather than a individual processing each one, so your application was marked for review do to some anomalies etc since you are not in the actual appointment and interview you will never really know what was said or not
it really depends there are many variables and a well presented application is key with supporting data - I’m Canadian and my wife received a ten year visa for the U.S. when we applied for tourism etc the main things looked at were savings, long term employment history and purpose of the trip etc
It’s possible that your Thai girlfriend has applied for visas in western countries previously so if the information doesn’t line up its declined all the western embassies share info and data centres as part of security etc
Depends on the quality of the application by your wife? Bad candidates often get rejected, good candidates get approved - people processing these look at thousands abs thousands and the bad ones stand out
how would the school know your true relationship to a child? Anyone could seek such a letter from a school for unethical purposes - a birth certificate showing you are the mother and registration at the school should be enough to satisfy that you are in Thailand to care for your daughter in school? You need to hire a Thai interpreter or volunteer to go with you because honestly it’s likely all being lost in translation - or hire a agent to sort out the visa issues it’ll probably save money and headaches