Good Idea Oda, but how about splitting Technological up further into, say Military and Economic.
So, the first would be the technology used in the construction of units and purely militaristic improvements Wonders etc. wheras the latter would be for strictly standard improvements, wonders and infrastructure.
So, now you would have Cultural, Scientific, Economic and Militaristic Tech types. With each one being 'harder' to trade than the one below it.
Whilst on these tech groups, I think that these would be good, general categories for tech research more generally. For instance, instead of saying I WANT to study monotheism or I WANT to study republic. Instead you say, I want to invest x% of my science budget into Cultural research, and x+1% into Economic research etc. The more you put in, the more quicker you will get techs of this category. The base rate at which you discover a tech of a given category would also be influenced by your civ characteristics. For instance, militaristic civs are, obviously, best at researching military techs, but worst at cultural techs. Religious Civs would be best at Cultural techs, but worst at Scientific techs. Scientific civs would be best at scientific techs, but worst at military techs. These are obviously just suggestions!
Obviously each civ has TWO (or more) characteristics-so I would suggest that these have an ADDITIVE effect. For instance, a Military/Religious civ would be ordinary at cultural techs, good at militaristic techs, but terrible at scientific techs. Obviously these tendencies can be overcome, to a greater or lesser extent, by how much of your budget you invest into those categories. Also, though, it is clear that if you invest in those tech areas which you are best at, then you will get more 'bang' for your buck-so to speak. Also, the rate at which you recieve a particular advance would be based on cultural 'flavours' as well. For instance lets say you have invested in Cultural techs, and you have a chance of recieving monotheism and Eastern Philosophy. The one you get first will depend on your culture group. For instance, as an 'Asian Tech', you would be more likely to get Eastern Philosophy if you belonged to either the Asian or Oceanic culture group. Whilst you'd be more likely to get Monotheism if you belonged to the European or Middle Eastern culture group. African and American culture groups would, all other things being equal, have a 50/50 chance of getting either one first!
Also, Oda, I think that cultural flavour of a tech should influence both the X you mentioned in your post, but also the value of a tech in trade to a given civ. For instance, lets say that China has an economic tech with an 'asian flavour', he is likely to demand much more for it than a tech with no flavour. By the same token, China will probably pay more, for the 'asian tech' than for a 'non-asian' tech.
Lastly, I was thinking that, for the purposes of science investment. It might be best to put techs into more categories. So, for instance, you would have naval, cultural, scientific, commercial, militaristic, industrial and commercial tech streams.
So, what do you guys think?
Yours,
Aussie_Lurker.