The first weekend in March isn't typically too bad for crowds. You are correct about Pirates being closed for refurb along with Matterhorn. From the restaurant, you can see the preload queue, the boat launch, and the swamp area. After that, the rest of the ride drops below your view. I'd say it's still worth going, and you still have a lot of rides to choose from. Are you visiting DCA as well?
Yes, I will be visiting DCA as well. I'll probably be spending most of my time at Disneyland, however, especially with no Tower of Terror. I'm looking forward to seeing the Star Wars Land construction!
The park (along with California) has been subjected to lots of rain, and in some instances, has closed early. Just set your expectations if this happens, but so far the forecast looks clear of rain around the time of your trip.
Yes, it sure has been rainy lately, and I heard about the early closings. I'd honestly be fine with rain as long as the park is still open, as that tends to lessen crowds.