@capo
I can totally understand that you would like to build your own mod from scratch for the purposes of learning and understanding. The suggestion is that there is still so much to do. If you were to take a working base like RevDCM, you could then build on uncharted and unexplored territories like merging and testing things like Jculture and many other interesting variants that have not been tried with RevDCM. The only difference that RevDCM has on fundamental grounds with vanilla bts better AI is the issue regarding the Manhattan project and it's historical connection to the DCM mod (all other issues can effectively be turned off and restored to default). In RevDCM manhattan is a national wonder as per DCM. I have offered to convert it back to stock BTS, but people actually either have no problem with the way it is in DCM or in fact like it. Thus I cannot actually put it back to stock without making many people unhappy! You will find that this only difference is very tolerable. The other advantage with using RevDCM as a base is that it has ongoing support in SVN and is the mod of choice for one of the best modders on CivFanatics, Jdog5000. He is intending to modify the spy AI and this will have repercussions upon this modcomp.
EDIT: The main issue with RevDCM is multiplayer!!! It is totally broken I think. I am looking into it.
Cheers