Yeah Balance mod is actually not for SE4...
My favorite mod was Proportions (only works on 1.91 though like basically all the cool mods except some few still updated ones)
http://www.spaceempires.net/downloads-details-532-Proportions_3.0.5.htmlwhich I merged myself with
Fyron's Quadrant Mod Deluxe
http://fqm.spaceempires.net/and image mod.. (needed for FQM)
Besides that there is also AI Campaign for 1.91
All can be found here ->
http://www.malfador.com/se4mods.html with links.
If you have the steam version of Space Empires IV then sorry to say, but you gotta pirate an older version and patch it to 1.91 ;p Since Steam version is by default to 1.94 for which I never got a merged FQM and Proportions mod to actually run. Not sure if they run without each other, but who wants that!
Sidenote: I got the Original SEIV Gold CD
And here you can find all (currently and still) updated mods, it's not a lot..
http://spaceempires.net/Currently and if you are on 1.94, ReStock Mod 4.0 sounds like the best one to have for AI play.
Here is forum with mod talks
http://www.spaceempires.net/forum-4.htmlrestock Mod needs latest image mod
Anyhow.. I feel like testing Restock 4.0 Because TDM AI + FQM is a good deal to have, and otherwise it sounds interesting
So.... Space Empires 4 ftw ;P