I'd have to agree with you on ALL of these points and a few more.
1. I think that if there is a pantheon of GREAT historical mods for the TW series games it would have to be these.
RTW-EB (Europa Barbarorum)
BI-IB (Invasio Barbarorum)
M2TW-SS (Stainless Steel) or BC (Broken Crescent)
2. EB has taught me things about history that i never knew, even after years of being a reader of these kinds of books. For instance i learned almost everything i know about the Arche Seleukia from EB. I knew before EB that it was a Successor state based in Syria that was conquered by the Romans. After i discovered EB i learned about ppl like Antiocus the Great and Antiocus Soter. I learned that there were a ppl called the Galatians that were Celts that invaded Turkey. I learned about Baktria's history in depth. I learned of the Konion Hellenon.
3. Id have to disagree with you about the best musical score. My fav is the German/Celt one. However i do agree that whomever did this must be a music fanatic, and cared a WHOLE LOT about what he was doing.
4. All of the AI problems/ the imbalance problems are the fault of the vanilla programming. The EB team has done their absolute BEST to cover these issues and for that i thank you. The only real complaint i have about the game are the stability issues that cause so many CTDs. For me 1.2 erased many of those, but they still happen from time to time.

Honestly if it wasn't for the copyright issues i would ABSOLUTELY tell the EB team to sell this product.