I have rode my rocket in the rain many times, only had trouble once while riding coming to a stop light the rear wheel locked up on oil slick in center of the lane. I would advise, when riding in the rain at stoplight intersections stay to one side or the other of the lane you are in. It seams to be better road quality/less oil from the klunkers.
The only time I have ever dropped the bike was in the rain: rode home just fine, pulled up to the garage, flipped the kickstand down with my soaking wet shoe, and stepped off of the bike to open the garage door. well the bike almost got the back of my legs as it fell over. laying there still running was a sickining feeling. I hit the kill switch.
Morale of this story: when everything is wet and slippery, always focus on that kickstand to make sure it flipped all the way forward. Bob