The removal of the resource rush isn't about balancing the game; it's about reducing the number of rules and the number of controversial situations.
Well, controversial situations only arise due to a lack of knowledge of the rules. And if we follow the logic that if a trade exists, rules aren't needed, we could remove restrictions on certain castles, but would it be interesting to start, for example, as Necropolis every time without any money? I don't think so. I believe we should strive to balance the game for two players, and the lower the trade value, the better. Besides, depending on the situation, the resource rush can give a very large bonus, or it might not give anything at all, meaning the trade will be a gamble.
Added 1 minute later
Dim, believe me, I've considered and played through all possible and impossible situations on all versions of Jebus. I believe that since there's no resource rush on HL+U, there shouldn't be one on Jebus and Diamond either.
Well, that's certainly a strong argument :D :D
Added 3 minutes later
By the way, I think we could remove the resource rush on Diamond; it's unlikely to significantly affect the game after turn 121, and besides, replenishing mana with blue mana is quite useful.