hi, those id drawing are only in estimate dimensions from floor plan, as for design diff than is weird. Now a day most id 3d is cut and paste, so it might be diff. In order to take out those rust stain on pipe is easy, just use metal polish will do. (plumber brought from a shop that keep too long) for electrical submittion to get approval by SP service, 1st u need to pay for inspection (testing) by SP 2nd ur quote will be higher. as for electrical trips might due lot of diff thing,eg like thing u use. Hope my little knowledge help u.