What tips can you give me for riding home in this bad weather on my motorbike?

You appear to have the requisite commonsense. I would concur with the reduced speed and be extra careful on bridges as the gusting will be sudden and strong over these structures. Great bike by the way. I am old enough to remember when they first came out. Speed Twins, Thunderbirds, Trophy, Tiger 100 and 90, Tiger Cub (useless). Ahhh those were the days.