What line to take;
Well it's a compromise depending on all the usual factors I'd just do as the other posters have mentioned and in addition watch out for the crap on the road ie leaves, mud white lines speed bumps (that magicaly disappear in shit weather until your on top of one) and numpty's. So don't hog the curb or ride in the centre of the road.
Keep it smooth. Speed entry to bends is always a fun one to get right so it's best slow in quicker out. Use the rear brake before your entry and if necessary just trial in part way toward the apex.Slowly & progressively increase the exit speed to give you a clean pull away fom the apex. Don't tip the bike into bend judt allow it to settle. Stay smooth and fluid and the bike will happily chugg around. Feel the grip.
Visor. I leave the visor open just a touch for most low speed ocassions and use the vents the rest f the time. You can use and furniture polish (Pledge) on any scratches and this makes the water run off quickly. Keep a moist (non alc) wipe in your kit so that you can clean. All major gloves have a soft patch of leather on the left hand glove keep it clean and it will work.
Head light check the earth connections in and near the headlight, also might find signs of arcing on a wet junction. Check to fuse and fuse box any signs of water? Check to subcircuits.
Hope this helps.
'WHO CARES WE NEVER WIN...........'