the idea of the trade resources helping tech research is a good one. also, i might be wrong here, but isnt it something that is easily implimented??
i thought along the lines of a +1 /month to whichever it is targeted to, maybe a +2 for the very valuable trades
well im going to write a list, tell me what you guys think, and if you think it can be done
before i start this i want to say that i think each trade should target whatever tech group it most closely fits by the description of that trade in the EUII user manual (pages 46-48)
TRADE BONUS
Chinaware +2 Stability for Latin tech group
+2 Trade for all other tech groups
Cloth +1 Infrastructure
Gold +1 Infrasturcture
i thought to go with infrasturcture for gold
because of the mines needing to be built,
but stability could also make a case
Copper +1 Land
Cotton +1 Infrasturcture
Fish +1 Naval
for those who do not have the user manual,
fish is decribed as an industry, not a food,
and a fishing industry is the beging of a navy
Furs +1 Trade
Grain +1 Stability
people gotta eat
Iron +1 Land
Ivory +1 Trade
Naval supplies +2 Naval
I know naval supplies is not a very valuable resource
but since it is named so dedicatedly to the
navy, I thought a +2 couldnt hurt
Salt +1 Stability
helps preserve meat, people like meat
Silver +1 Infrastructure
same as gold here
Slaves +1 Infrastructure
this one should be infrastructure because slaves can
help out in other areas around your nation,
I thought maybe after a time a -1 stability
could be aplied, but dont know if possible
Sugar +2 Stability
pretty much the same as salt, only better
Spices +2 Trade
unlike sugar and salt, spices were the main cause
of europeans attempting to sail east,
therefore should deal with trade, not
stability
Tobacco +1 Trade
its new to europe, so everyone wants it
Wine +1 Stability
this one i choose because of the way the user
manual describes the importance of wine
in daily life. A bonus for trade could also
have a claim though
Wool +1 Infrastructure
there are a few that are left out of the user manual
Tea +1 Trade
Tea trade was a big thing of the times
Coffee +1 Trade
pretty much same as tea
and as special bonus should be in place for any nation that is the leading trader of a single resource
if you are the leading nation of trade of producing a resource you should get a additional +10 bonus to the same tech group that the resource aplies to
i.e. russia is the leading producer of grain(always

) , say they have eight grain producing provinces, their total bonus from the resource of grain would be +18 / month. (8 from provs, 10 from leading producer)
now , if implimented, there would need to be a little tweaking of tech research , maybe a slight increase in the multiplier based on nation size, because , as you can see, a large nation can very much help to speed up tech developement.
anyway , please reply with your comments , and ideas, and thoughts on how, if possible, we can get this into a mod