I ride pretty much every day, rain or not.
With modern tires traction is pretty good generally, yes I slow down, yes I'm gentle on the throttle and brakes, but even slick spots aren't an automatic crash, just stay balanced and don't let the bike lie down.
Metal is deadly. Painted lines, meh, NOTHING on a wet man-hole cover or railway lines.
The bike probably stops pretty good, the vehicle behind you , probably not so good. Leave more space - being hit from behind probably hurts less than being squished between two cars and secondly if you hear the dreaded "screech" from behind it'll give you more room to do a high speed lane split.