I second that but then again a game that's not prone to exploit is a rare thing. Come to think of it, is there such a thing?
The problem in this game is that I get in doubt on what is an exploit or not. The AI will agree to stuff I consider very stupid. Like selling galaxy map, the price is even dependent on new value, so you can see how much new stuff they have to offer...
Putting contested bases just to sell them... That is very much an exploit. Seeing the AI just about to destroy the gas mine they declared war because of? Pause, negotiate peace, use the gas mining base they value highly (which as 10 seconds to live), and grab whatever else they got that you fancy. Not quite as exploit, but. If you are really lucky they got more mines they want, that will make them declare another war in some time. More cash and tech!
I consider having construction ships built as explorers (to be built on space ports) an exploit, but that is probably just me. It should not be possible. Other ship designs are something of the same (Cruiser strength explorers with long range scanners?)
I also consider the tech trading activities suggested exploits, but that is just me. The problem is that the AI does not do that kind of things, and that it is very profitable. And very profitable makes the game very easy.
I feel too good resort base setup is approaching exploit. Because it is too good. But that is just me. They are unbalanced.
I feel the built in way of the ancients works like an exploit, but that is a core game design feature. I think the AI can get them too, though, but not through the story.
So that there is quite a lot that is very nice for me, that i don't do, for some reason or another. Basically any too good idea the AI does not abuse works quite like an exploit.
If the AI did some of the very good ideas you discover, this game would not be newbie friendly, though. At all.
Now, if we get some more game setup options and difficulty sliders. Most of these things may not longer be exploits. They may be required to survive