Even with the 50% economy building, I still have a very hard time keeping the Iconians out of the red. My complaint with them is similar to what a lot of people have stated. I'm not sure who they're supposed to be. In DA, they struck me as slightly evil super-scientists. Now their backstory seems to suggest that they would struggle with science.
Maybe they don't struggle with science, exactly. Maybe it's more of a predilection to be somewhat lazy about it, since they have Precursor tech to fall back on. They're used to having their tech handed to them on a platter, as it were, and it's not that easy for them to make a leap to developing their own inventions. Actually, I see a lot of their Precursor-related tech tree as being sort of an archaeological project... with Iconians out somewhere digging up Precursor artifacts instead of working hard in a lab, each time they "research" a new tech in the tree.
I agree that espionage has nothing to do with this race. We already have a spying race. Their super ability is pretty weak. If you are unlucky with planet placement, their super ability is completely useless.
Yep, tell me about it... my current Iconian game had not a single aquatic or toxic world I could take advantage of, in the initial colony rush phase. It's sometimes useful later in the game, but I think it's the only Super Ability that depends on a dice roll to be useful or not. Super Adapter also isn't the best match to a race with a weak economy even when you do get lucky, since having access to a lot of planets in the early turns just deepens the eventual economic crash. An experienced player can avoid that by holding off on the aquatic and toxic worlds until you think the other races have tech'd up to grab them, but it can bite a new player pretty hard.
In keeping with their backstory, why not give them some sort of Precursor related super ability? For instance, they could have a chance to discover tile bonuses when they terraform. Guaranteed at least one tile per planet? Or perhaps an increased chance of Precursor ships? Or pretty much anything besides what they have now.
That would help, although I'd like to see some kind of direct cash infusion that would happen earlier in the game. Maybe an increased chance to find cash-producing anomalies, or a chance to find Precursor artifacts that could be sold, every time you colonize a planet. Or a slight boost to tourism, based on the idea that Precursor artifacts would be a strong tourist draw?
If we are going to give them the ability to colonize extreme environments, aquatic should be removed and given to the Torians. Korath already have toxic, so let's give them radioactive. You could say that it's due to their constant use of Precursor machines, which are lethally radioactive to most other races.
I like the idea of swapping aquatic for radioactive with the Iconians, for the reasons mentioned, but I don't think the Torians should get aquatic colonization as a starting ability. It does make sense, considering their background and tech tree, but Super Breeder is already a strong bonus. I'm not sure they need even more planets in the colony rush to breed on. Torians usually do pretty well in my games.