Regarding cloaking, that's also a good idea, but I doubt that could be included without a significant amount of coding of the AI to use and counter it effectively. I reckon the developers would already have enough on their plate trying to balance 12 different tech trees. GalCiv 3 maybe?
The idea of cloaking was just a random thought, brainstorming.
However, as I understand it, even that should be simple enough with the expansion. As is, they will likely be creating some sort of command ship, to travel along with a fleet. As I recall, some of the new items were ship components that affected the entire fleet. You wouldn't put these on every ship, just one ship in the fleet. The way I would do it, is make my basic fighting ships as the core of the fleet, and then make one command ship which would have all those fleet bonus components. If they are already adjusting the AI to deal with these fleet wide bonus things, then it wouldn't be more work to just toss in the cloaking detector (sensor) component onto that command ship also.
As for effectively "using" cloaking, as opposed to "detecting" it, they just apply a priority to the cloaking device. Probably somewhat low priority, putting engines and weps as a higher priority. But, if the space is available on the ship, one gets added after the higher priority items. And then, with this method, different races can have different priorities and may rate a cloak higher then defenses, or higher then weps. You would have races that use it a lot, and races that use it much less, or only after everything else if it still fits.
I don't see any really extreme difficulties implementing this. However, it was just a random thought, not something I expect. But it should be feasible without too much work, if they wanted to do it.
I would then add to the two components, another planet based cloaking detector to help cover planets better. Then again, you could just argue that a defender around a planet has that task and we shouldn't take up another slot on the planet itself. Either works. In fact, you could even make the cloak a device that affects the fleet and goes on that command ship, if you wanted. Or you could have cloaks and/or cloak sensors as a device on star bases. There are loads of options here, really.
I don't think they have to actually program the AI to launch massive sneak attacks or actually do anything special just because they have cloaks. They still interact and act the exact same way, except you, the player, may only be able to see half of their ships. Or perhaps you can't really see more then about 5%, depending on what priority a given race puts towards using that cloaking device. Nothing else spectacular needs to be coded.
Perhaps stronger cloaks are needed to block out a sensor. I have a level four cloak detector, but wont be able to see your ships with a level 5 cloak. Or perhaps its the range with which you can see them. Higher level cloaks make it so you have to be right up close before you can finally see them. Of course, if you accidentally move onto the space of a cloaked ship, you should get a pop up with 1) attack, 2) cancel, and it would reveal the cloaked vessels. Seriously, this isn't outrageously difficult to code.