...and it's a steel frame with a steel fork, which is contradictory to "a light frame; I'm no expert here, but thousands of kms I made riding on a heavy steel frame taught me one thing: a good bike is a light bike".

The weather performance of rim brakes varies greatly, mostly depending on the brake pad used. A number of people on this forum have said that they get good wet weather performance with the "Koolstop Salmon" (they're salmon colored) brake pads. I own a pair, but haven't had a chance to ride in the rain with them yet. I wish I could offer better advice on disc vs rim brakes in the wet, but all I actually know right now is that disc brake road bikes aren't the easiest to find, but they're always heavier (wheel has to be built stronger, discs take up slightly more weight, tend to not come on the lightest frames, fork almost never carbon).