I have no idea where you refer to but the installation I worked on did not have any 2.5mm bridges. Regarding the 25-20A breakers, some aircons require more than 20A to start whereafter their consumption drops. The motivation of providing 16A socket outlets is ridiculous. 4x6A loads is 24A, well within the capabillity of a 2.5mm cable. The other items you mention were also not at the complex where I worked.