I'm not sure about everything... but hopefully the following helps a bit.
Jungle Cruise and It's a Small World are often still closed the first week of Feb for the holiday removals. Should be open after that. The water rides often go down during this time for maintenance, primarily Grizzly River Run in DCA.
The railroad, mark twain, and fantasmic should all be up and running again this summer. However, I think 2018 is going to be very unpredictable for the northern part of the park if Disney is pushing for a Dec 2018 Star Wars opening. It wouldn't surprise me if we see Toontown and the Fantasyland theater (Mickey and The Magical Map) go down for extended times. Also at some point work is probably going to need to happen in Critter Country, but not sure if that will impact Winnie the Pooh or not.
Regardless, I would think it would be a good time to visit as I think things are just going to get more crazy as Dec 2018 nears.
Weather in February in Anaheim is unpredictable. Expect anything between beautiful and sunny 70 to gray and rainy 50 degrees everyday, with colder nights.
Hope this helps!