I can figure out how much stuff a relatively friendly NPC empire has, because I go to "demand" and ask for more and more until they suddenly have -1000 for the offer. That means they literally do not have that much.
I was actually wondering if that was a way to cheese it to find out. Admittedly, I've only ever offered a trade deal exactly once, which was to give away a lot of food I didn't need to a neighbor who had treated me nicely in the past, in exchange for an active sensor link. They told me to shut up, so I haven't bothered to try trading since.
I usually use trade to give away a surplus resource I have for a resource I need (usually energy) to buy something, and that usually goes pretty well.
Yeah same, which is probably why people are trading away food so much. Except that I don't mind keeping a food surplus, personally, since it's a nice way to slightly boost my empire (population growth) without micromanagement. It would be really nice if mineral and energy surpluses had similar minor benefits, if only to let me relax about them
Instead of stacking 1:2 trader enclave deals, and desperately offering my bounty to other realms for research treaties or whatever. I just hate seeing it flat-out wasted.
It's usually energy, since minerals are easy to blow on ships or habitats. Policies are not enough of an energy sink ):
In theory I guess I should just go way over my supply limit until my energy budget is balanced, but bluh, and diminishing returns.
Re generously offering food for a sensor link: Sounds like an issue with their government type, I would guess. I seem to recall Honorbound Warriors for example refusing or resisting a lot of objectively good deals, due to their principles. Maybe not a bad thing, since it supports their supposed character with actual mechanics.