My suggestions:- try not to ride over metal in the road, it is very slippery and your tire will slide on it even without brakes. Everything else is relatively ok. If you have to go over metal release all brakes and go straight.

Grip in the wet also depends on the compostion of the rubber in the tread. I believe the compositions that have less hysteresis and rolling resistance also have less grip in the wet. I dont have any data, but this is what I read in an article on motorcycle tyres in the 1960s.