If your frame is steel, make sure to wipe it down so you don't get rust. I use the same oil year round, but end up applying it more often in rainy weather. I wouldn't be to concerned about tires, I run with only a small amount of treading and have no issues, if your concerned just take the corners a little slower and break a little earlier until you get used to it.
However:
Watch out for metal on the road, things like man hole covers become very slick, and dangerous, in wet conditions. Also, if your in an area that doesn't get a lot of wet weather, there is a chance the roads will have some oil come to the surface, which would also make conditions a little slicker.
I'd suggest asking in the commuting forum also, due to your winter conditions rarely getting under 50, just expect the first 8 responses to talk about how much you'll absolutely NEED fenders.
That said, you may want fenders, I personally don't use them, but I have a shower at work, and have enough cycling clothes to rotate through.
Also, you may want a thin outer wind/water proof layer. Once it gets 55ish the rain goes from being pleasant to being a serious heat draining issue.
__________________
In the words of Einstein
"And now I think I'll take a bath"