Only one thing to say here: read all tooltips and remember. There is so much information ready at one's fingertips in the population screen* if one has the patience to look and once one has learned the basic principles one seldom needs to look again except when POPs start acting in unexpected ways.The other is understanding the indirect effects of what's going on - as you say - the unintended consequences - where altering one lever somewhere effects a factor, which affects something else in the model that you didn't think of before.
* and elsewhere, but central to understanding V2 is POPs, so that's where one should begin if one seeks understanding.