All true. I used to never use slavery or raze cities, but I've learned to distinguish between doing things in a game that are immoral in real life and doing things that, in my view, subvert the rules of the game for unfair advantage. Again, I only play single player so someone else having a different position on what constitutes an exploit doesn't harm me any.
Here's a tactic some might consider an exploit. When beseiging a city with many archers, put a warrior *alone* on some square without a road, hopefully not a hill. If there are three or more archers, one will probably attack the warrior. The archer will probably win, but will be wounded and outside the city, making it easy for your axemen or swordsmen or horsebowmen to kill it, which will make the city much easier to capture. Sacrificing an obsolete unit and taking damage to one modern unit is a very good ratio for taking out an entrenched defender. I call this a possible exploit because a human would not be stupid enough to fall for it, but on the other hand it has huge historical backing (the Normans conquered England largely because Harold's Saxons broke ranks to charge retreating Normans, the Mongols also used this tactic.)
Here's a tactic some might consider an exploit. When beseiging a city with many archers, put a warrior *alone* on some square without a road, hopefully not a hill. If there are three or more archers, one will probably attack the warrior. The archer will probably win, but will be wounded and outside the city, making it easy for your axemen or swordsmen or horsebowmen to kill it, which will make the city much easier to capture. Sacrificing an obsolete unit and taking damage to one modern unit is a very good ratio for taking out an entrenched defender. I call this a possible exploit because a human would not be stupid enough to fall for it, but on the other hand it has huge historical backing (the Normans conquered England largely because Harold's Saxons broke ranks to charge retreating Normans, the Mongols also used this tactic.)