Aye, they are valid concerns, and it is making me focus on a section of the code which I am finding is VERY lacking in quality. But it isn't as simple as "defer to how FfH did it" in this case, which is where the nuisance comes in
What is happening is a cascade effect. We modified something which has caused the Barbarian presence to hurt more (I'm not entirely sure what it was, but hopefully it gets sorted out shortly). This slows down player research. The reduced player research brings it down to a level which should be impossible to survive with, which happens to mean LOWER than that of the Barbarians (because they do research, much like any other Civilization does, but get a bonus to their research rate if other civilizations already know the technology).
In a normal game (barbarians are not able to hold cities long, players are racing to technologies), Barbarian advancement is almost a standstill. But when the Barbarians are able to not just hold a city or 2, but control half the world or more... They can become the tech leader because there exists no reverse mechanic (Barbarians are not prevented from being the first to discover any technology)
As stated, this is something I would never have paid any attention to, because the important key is where the Barbarians are NOT mentioned, which you don't see unless you are looking specifically to have them get special treatment. So unless you are studying Barbarian behavior, the code in this area looks flawless and wouldn't be deemed worth adjusting. So it is great that you bring it up, but the crowd-pleaser in me cringes to hear the same issue brought up 20 times with the assumption that it is something we have done wrong and can easily undo
Anyway, come christmas break I am hoping that the Barbarians take a remarkable turn for the different (and more fun/balanced/tolerable)