Realistic world suggestions

We can introduce new rules in realistic world to make it more interesting like-:
1) we can have rules like starting international operations after serving domestic airports for some years like in India 5 years is the time .
2) minimum no. of aircrafts required to start international operations.

Thing is, restricting international service times will kill people who set up hub in HK or Singapore and others. May work for some countries but people wont like the rule