How do you test stuff (or, is ethical behavior dead)?

[JonBrave]

I keep reading about people "testing things out". Just how do you do that in this game, please?

Early in the manual it told me about it had an "unusual" save game. As I understand it: it only allows you to have one save game (per game). In other games, typically you could save after each turn under different name, and restore as you pleased. In this one, when saved, there's "no going back" (and there's no auto-save). I assume that it only saves if you click "Save & Quit"(?). So...

I guess you must save, then try something next turn, then not-save-but-reload to get back where you were?

My question there is: is that "ethical"? Is that what you are intended to do? Or, is saving/loading only for switching off, and you mustn't reload to try things?

If you do try something and save as turns go by, then your old position is gone and you cannot go back, right?

I only play SP, so MP is not what this question is about. Thanks.