... proportion of of research "invested" in agricultural tech will be equal to the proportion of land/population alloted to agricultural use. Investment in the scientific sector will go mostly to the "learning" research category, with a smaller boost to all the other categories. Increasing investment to the research sector would increase this bonus and make discovery of "learning/theory" category stuff MUCH faster.
The current plan is for each tech to have a set cost / turn in research points (RP) and number of turns to research. The player would enqueue whichever techs s/he wishes to research, and as much RP as is available is applied (in order by queue) to techs. The amount of RP available is determined mostly by planets' populations and current research meters, though a few other sources might exist. There are (currently) no "types" of RP for each category, nor ways to alter the cost of techs (though that might change, I suppose).
Your suggestion might be possible, but it would probably need to be molded around the system as it is now... (Can you suggest how to do so?)
P.S. where are the current_science and max_science files located? I could not find them for reference.
The what? There are meter values called "CurrentResearch" and "MaxResearch" on planets, and a "ResearchProduction" for empires as a whole, but I have no idea what "files" you're referring to...