We had foreign banks who advertised that as a strength and sent their profits to their countries. But when there was a crisis they said we are just a local bank with the same brand as a US bank and won't give the customers their savings back.
I don't know about orbiter but FlightGear uses JSBsim for flight dynamics modeling which can be very accurate and was even used at NASA.
You are correct that as space is not the primary use case for FG the shuttle developers had to start from scratch on many things.
Sure, also it works for me because it is on a system that is frequently turned off.
If it would have to stay on for a long time it would fill /tmp with garbage.
That made me remember having to update the BIOS firmware and doing it at 3AM and on a night without wind when there was almost no chance of power going out.
You don't need batteries, you just learn to save your files often.
I live in the third world too and can say that even with crappy power supplies computers resist quite well blackouts and brownouts.