Thanks for the kind words :)
The upcoming update will have a few improvements to traffic lights to make them less tedious. Mainly the ability to copy lights similar to what you suggested and also being able to click+drag on the traffic light wheel,
I'm having a think about a "master traffic controller" sort of feature but it obviously requires a bit of thought to do properly. So it may or may not end up in the game depending on how much I feel it is needed/how difficult it is to design.