Paralysis of analysis...happens to almost everyone at some point or another. You seem to have looked at a lot of bikes. At some point, you will just have to pick one and start riding it. Almost anything on a bike can be changed, short of the frame itself. You are not locked in to any groupo, so sweating over that is just wasted time in the end. Get a quality frame, upgrade the drive train and control systems as things wear out over the years.