So what are the disadvantages of this strategy?
I'm still in the beginning stages of a test game where I plan to rely solely on an EE if possible after literature (I feel the exact start point can be a bit flexible, I happened to get marble close by anyhow) so I'll probably discover things on the way, however..
The most obvious drawback that I can think of right away is of course that you can only steal techs that have already been researched. This means you wont get any great people from techs, you wont win the liberalism race, and you won't be in a position of out-teching your opponent militarily unless they're a backward civ. A further problem with this is that it will be harder to get good tech trades since that often hinges on you having a tech that is not well spread and then trading it to several opponents.
I also suspect that you will encounter a make or break point in the middle game where you haven't yet developed your spy infrastructure enough to compete with your opponents library infrastructure. The EP boosting buildings mostly come later in the game, jails and security bureaus for example, are not until you approach the industrial age.
However this should be offset some by so far outproducing the AI in EPs that tech-stealing become much cheaper in the commerce required than actually researching the tech yourself.
Another thing that I have thought of is the importance of culture and the dual function that libraries fill here. In my current game I play as Napoleon and my closest neighbour is Kublai Khan. Bad news for culture wars. I'm going to be forced to either go to war very soon or build some libraries to complement my monuments or start to lose land to a superior culture. This makes me think that creative could possibly be a strong trait to use with an EE, especially on maps where you are likely to have several neighbours. Unfortunately, beyond the automatic 2 points of culture that creative generates, you wont have much use of the trait if you're going to ignore library building for the most part.
Well..back to testing.
Also, thanks for the link Bhruic, I'll read it later.