OK, my experience.
Technically mod is outstanding - no bugs, great UI, many options included.
Haven't played MOO2 this century, so was kinda rusty, played several games on just hard, decided than with better micro, shipbuilding and custom races at impossible there will be the same results. Stock races (Humans, Sakkra, Klackons, Silicoids), pre-warp, average age, 8 players, 1,5 improved and ICE map script.
Tried different map settings, medium 1,5 improved was best for me - ICE map feels just too prosperous, too many big habitable planets all around. Small size is too crowded, large too annoying at the later stages. Middle size map provide enough space for early expansion, couple of systems to settle, and then conflict with aliens with scrapbuided fleet, then grand finale in a reasonable timeframe.
Somehow on the fence with ICE(m) vs 1,5 improved. In general tech tree changes in ICE feels right, but I got problems with Robotic Factory and Subterranean farms being too early in the tree - Robo-miners and Soil Enrichment are kinda dedicated techs for production and populous worlds, but factory and farms I was building all over the place. Maybe it's balanced, so with 6 free food on each planet non Lithovore races can compete, but feels kinda boring. Research Lab as a singleton is fine for AI, but my uncreative klackons got it also, which kinda kills the point of disadvantage. +/-20 picks at race customization is too much, IMO.
Find pattern in all games on both 1,5 and ice - early game is quite tense and packed with decisions, as AI is quite fast with first colony ship and early military. I'm trying, if not repulsive, to sign as much research/trade agreements as I can, to get positive relationships and sign nonaggression pacts. Usually this plan fail with at least one neighbor, it leads to war when AI got superioor fleet, but AI blokade with destroyers-cruisers I can beat, with lone battleship they like to attack starbases and are usually failing terribly. Then with optimizing race bonuses and available technologies nearest AI can be beaten, somewhere at this time I'm managing fleet to beat nearby monster with juicy planet and make production hub there stacking as much production bonuses and corresponding leader. Maybe one more such hub on the other side of my territory, every other planets go into science, than I can spam battleships and later titans and roll over the galaxy.
Until the last game. Hard difficulty, medium 1,5 map, ICE M, stock Klackons. Uncreative rolls was quite interesting - I was actively tech trading, but got Automated Factories very late, cannot get Spaceport, Merculites, Fusion beam, Type 3 shield, so was struggling both economically and militarily. I've managed to get Stock Exchange, got my Battleship spamming factory working and managed to hire "android leader", so it seems that I will start to roll, but it was quite challenging finally.
So it seems to me that too make AI competitive best way to go is not singleton techs and moving them up-down the tree, and even not AI bonuses, but just serious nerf to production and science buildings. For a player it should be serious struggle when and where build each of this buildings, not just spam most of them to get good results all over the map (or not spam and get mediocre results even with Klackon economy bonuses).
PS: Will play ICE from now on even if I'm not sure about some tech changes - I got my usual "final horde" but Psylons managed to tech enough stuff so my spam of mass-driver titans work not so great and after them there is big Mrshan empire on far part of the map. So I will finally need to produce a proper end game fleet. Good stuff!