By the way, what happens when a civ's free techs are the same ones it gets as a handicap?
Nothing

Said in other words, the AI ( or the human in levels where the human receives free techs ) receives the X tech for free .... if he already has the free tech, too bad for him

That alone makes a lot of the diference between some civs in high levels : for example a civ that starts with Agriculture and Hunting ( Persia for a example ) in reality will only get archery as a free tech in Immortal while a civ that does not start with neither of those techs ( Portugal, for a example ) will start with 5 techs....
In fact I think human immortal/deity level tatics should actually be ignored. They are tatics for a very select situation ie where every one else is researching quicker than you.
I've been beating on this point for quite a while: human tactics in high levels are not necessarily good for the AI ... not only because of this point , but also because normally there is only a human in the game

If all the AI start acting like a human in high levels does today everyone would go to the lib path only to discover that no one would have any techs to trade with them

, just for a quick example. And to add, a lot of the tecniques used by high level players ( a thing that I consider myself to sort of be

in spite of there being a lot of players that are a lot better than me in terms of beating the AI out ) are specifically based in the fact that the AI is somewhat uncapable to see certain dangers ( like garrisoning heavily a recently conquered city with a heavy enemy stack filled with CR siege in a hill right next to it .... ) or the fact that the AI pattern of actions is clear as water to a experienced player (
a little of self advertisement here as a example ... nothing compared with HOF games OFC

Anyway this kind of analysis is only possible because of the knowledge of the AI patterns of action ....)
Getting back to the topic of the worker rule : regardless of how you look at high level strats, the fact is that the AI would win a lot by learning micromanagement of the high level players that do it right ( a group that I don't belong to

). In fact If I had to resume the principles behind the human MM in this early days it would be:
-Do what it will give you a faster settler and a stronger position ( with stronger I mean a aglomerate of techs, units, improvements ,population ,gold and some other stuff I really forgot to insert here

If would be good if the AI actually had such a number in mind when it makes it's decisions ).
This obviously would decompose in a lot of sub-rules , but in terms of worker start this would probably give in 90% of the cases the advice you hear a lot in Strategy and tips forum : "You should have a worker as first build if there is something for him to do when he gets out ( this obviously implies you don't start with a worker OFC, a thing that applies to the AI up to Emperor ... if you start with a worker, things are quite diferent and would be more like "See if you would be better with a second worker ASAP compared with other options

) ... otherwise better start with something else ( again a caveat for starts with seafood ... a pretty similar rule could be applied to choosing WB as first build

) .
Well, I agree with jdog that it should not be expectable that the AI integrates well tech choice and queue issues ( atleast without some heavy work of the coder ) , but it would probably be sensible to make the queue of the first city a little special

Atleast making the AI governor to look at what tech is being researched would probably help in here

( btw , confirm this to me : tech choices are made before the queue ones, right? If it is the other way around things are completely upside down

)