#4 HarryT,
That's an open question. It is one I (and many others) have had since the release of the game. I believe Nephrinn stopped posting his mods because of this issue.
I have played with most of the mods, and can say from experience the MV as currently designed will accept any mod by Frogboy, Duglis & Pierre-Luc. Nephrinn's are very well-balanced, but they were written for previous versions of the game, and I do not know whether updates are available.
JoB's mods are also very good, and the great majority are also acceptable. Only his Terraforming mod may be considered "unfair", since it allows the player to obtain (through tech research) the PQ+3/+7 benefits without spending racial picks on them at start. (Because of its powerful advantages, I have dropped it from my own MV submitted games. But it is a very fun mod!)
~SDC~