Espionage

No, you don't need to spend any more after reaching the highest level.

which is kinda dumb btw

Strange because I still don't gain any new techs when I reach this level which is Advanced.

I never managed to steal technologies by espionage, am I doing anything wrong?
Also, the manual claim that there is also Destabilization - where?

Destabilization isn't included in the release.

I though that if you kept spending, you will eventually steal techs from them...

I've have succesfully stolen a tech from the AI.... once....

It seems to be very very rare, and you have to be at max espionage.

If you put a decent amount of funding into espionage, you can steal a lot of technology. I stole about 17 technologies in one game. I did have a 15% espionage bonus to my civ though.

I have only stolen tech once as well. You don't need to be spending money to do it though. I was at advanced and had turned my espionage down to 0 already. Stealing tech through spying is just very rare because it is so easy to get to the highest levels. Personally, I think the frequency should but upped and the process of getting to advanced should be higher. Also, maybe it should depend on government type.

Also, it's slightly off-topic, but as long as I'm saying it, there should be additional advantages and disadvantages to different government types. Ex, Imperial is harder to spy on, Federation has more senate interference

Once you reach the advanced level of espionage, any further spending is wasted. Set the slider down to zero, and you will still get an occasional stolen tech. Keep in mind though, that you can only steal what you don't already have. If you aren't getting any stolen techs, you probably are leading the game in research.

On the flip side, getting lots of stolen techs is a good indicator that you may be falling behind in research!