[Alneyan]

The biggest problem of most mods is that they add nations, leading to possible major imbalances. I see no problem with using Zen's mod which currently changes Pretenders however; all players will benefit from this change, and not a single player.

In the case of mods adding new nations, the best way seems to require all players to play a modded nation, rather than mix standard nations and mods. There has been one such game on Mosehansen in the past, but you would have to ask the opinions of the players about how well it turned out. The purpose of such a game would not be perfect balance however, much like in the same way as some themes are weaker than others in the regular game (which isn't a bad thing if you ask me, but I digress).

If the mod you mention requires the 2.08 Version, it is comptabible with all Versions starting from the 2.08 patch. Requiring a specific Version is needed for mods using special commands, introduced by later patches (such as the shape change commands of the 2.13 Version). The only exception would perhaps be a mod altering one of the units modified by a further patch; for example, a 2.08 mod about the Dryad Hoplites (Pangaea New Era) would not have the Round Shields that have been given to the Dryad Hoplites in the 2.13 patch.