I live in Belgium, which is only marginal drier then blighty.
Things that can get rusty are, as already mentioned, center and side stand.
I commute every day, rain or wet. At night my, slightly faster, because silver :razz: , ST 04 sleeps outside under a roof. I would not cover it, the damp will stay in much longer. Better to leave air circulation at it to dry.
Hein Gericke make excellent waterproof gear. They have their main stream line with Sheltex and a bit more expensive stuff with goretex membrane touring suits.
Good CE protection as well and almost all with enough reflective material that you can use them as XMas decoration (when not riding off-course)
*** oh
NO I must be the first to refer to XMas ***