After reading through the posts here and playing through a Gigantic-Abundant game, I have some Ideas that could tweak the espionage system so that it would be more usefull and scalable to all galaxy sizes.
The first problem I noticed was that spies could only be used in an aggressive way. Now, I tend to play toward an influence strategy, and seldom get into wars. I really have no real interest in trying to cripple my neighbors. I am very interested in getting good intellegence on all my neighbors including minor races.
My suggestion is to have a place to put 'sleeper agents' for each race. These sleeper agents would not cripple any improvements, but would do the secondary tasks that agents do like getting intellegence on the civilization and having a chance to steal techs. The compensation for not taking out any improvements would be that they could not be nullified by other agents. This would allow you to gather intelligence without starting a covert war.
The second suggestion is a change to how counter-espionage centers work. Right now they seem to be a really bad investment in rescources unless you are working on a really small map only a handful of worlds. On gigantic maps where I have 200+ worlds building agents is so much more cost effective as to make them useless.
The only change I would make would be to make is to allow building a counter-espionage center to remove (not nullify) an agent from your world. The agent would be sent back to his home civs agent pool, not killed. This distinction becomes increadibly essential on Gigantic maps when you get the 'Every world gets a spy' event. On smaller maps, you have around 20 agents to deal with, which is a difficulty, but can be dealt with in time. In my latest game, I got the event and got 236 agents in my empire! This is an impossible number to ever negate. If I were able to remove them with counter-espionage centers, I could eventually remove them all. It would be a long tedious process, but possible. On the other hand, I do not see it as reasonable to have to build these structures on all my worlds simply to protect myself from a random event.
This leads me to the Super Spy Super Ability. All the discussions I have seen on the board seem to universally pick this as one of the worst and most useless super abilities. I would make two changes that I think would make this ability on par with other Super Abilities.
First I would give all their worlds immunity to agents being placed on them, as if they had buiult a counter-espionage center, without the morale bonus. This would make the only way to spy on them is 'sleeper agents' as outlined above.
Second, I would make their agents unkillable. Any time one of their agents was nullified, instead of being killed, it would be removed and sent back to their agent pool.
I think that this would make a Super Spy race one that could really use the espionage system as a path to galactic conquest.
These are my ideas that I think would make the espionage system much more flexable and scalable and make the Super Spy super ability one that people would rreally use.
Scincerely,
Scintor