Thanks. Some other thoughts that occur to me. As ever, disregard them if they are of no use to you.
A psychic or semi-psychic race ought may be more prone to groupthink than a normal civilisation. This is a phenomenom which occurs in tightly-knit groups whereby particular memes become dominant, possibly at the expense of more beneficial ideas. A typical example might be in a group of gamers that play Puerto Rico or Magic the Gathering where certain strategies become perceived as dominant and as a result other startegies are neglected. When a new player joins the group, they may have new strategies of their own which completely blindside the original playing group.
There are a number of ways this could be modelled within the game - the simplest being a flat science and culture penalty. An alternative might be variable tech costs - sometimes the dominant idea will be right and will circumvent a lot of trial and error, sometimes it will be wrong and will delay research. This modcomp might be useful:
http://forums.civfanatics.com/showthread.php?t=248981 if you decide to take this path.
If you decide on the simpler option of a flat penalty, then there needs to be some balancing mechanics. These can be used to give your Civ a unique playstyle, like the Khazad or Kuriotates, where the player needs to take into account the unique nature of the Civ they are playing. Crystal weapons which give a tech bonus for every combat victory have been discussed. An additional option might be a civilisation which gives a trait to every combat unit by the Myu a +1 Science and +1 Culture for every successful combat. Another mod which is almost certainly worth looking at for this Civ would be the tech by conquest mod, which grants bonus beakers upon the conquest of another Civilisations cities. You can find this mod here:
http://forums.civfanatics.com/showthread.php?t=245593
I'm pretty sure I've seen a mod which allows tech creep based on trade routes. Sadly I couldn't find it. The idea is that every trade route to a foreign Civ that possesses one or more techs you do not possess also adds an equal amount of science to one of those techs. For instance, if you have a trade route worth 5 Gold with the Sheaim who possess the Poisons, Corruption of Spirit and Iron Working techs, you would get 5 Science towards one of those techs randomly. This means that you occasionally get random techs, quite possibly in a tech you had no interest in researching. It also plays well with their general Lore. They (used to) worship Mammon, so running Civics such as Foreign trade and building commercial buildings plays into their hands.... and Mammon's as well.
As I stated in a previous post, there are some things in Erebus which it may be better to be ignorant of. The Octopus Overlords are the most obvious example, although Hyborem whispering into your dreams and meeting Perpentach for the first time may also prove exceptionally dangerous for the Myu. This could be modelled with a Dark Age, the reverse of a Golden Age (i.e. just multiply the bonuses provided by a golden Age by -0.5 to -1) To balance this Golden Ages could be rewarded at certain activities such as researching Strength of Will and/or building the Bazaar of Mammon. In addition, after experiencing a Dark Age, the Myu could use these memories to inflict a double-length Dark Age on everyone else as their world spell, essentially the diametric opposite of the Balseraphs.
Mind Stapling (which comes after OO on the tech tree and would hence engender experiencing a Dark Age) would be of particular interest to the Myu. One could envisage a new Labour civic - Hivemind - which further crippled their Science and Culture, but massively increased their productivity as a result.
Finally, another mod worth a butcher's, more from a flavour perspective is the Show Hidden Attitude mod. Sometimes the AI hides it's true feelings, so although it states it's attitude with you is +5, it's actually only +1. This mod
http://forums.civfanatics.com/showthread.php?t=335966 reveals their true sentiments about you. A psychic race ought to benefit from this mod.