Precision Building is a novel idea, but I feel it's too powerful as-is. Played immediately after Forced Labor, it would almost certainly give a tower victory. Perhaps it could average out their heights? It should be taken into consideration, though, that wall if far cheaper than tower.
Really, I don't mind your suggestion for the wall building or brick gaining portions, but the tower building is too powerful. I'd suggest having just that condition one, where wall is greater than tower, average the two rather than raising the tower to match.