I just got my first Uros and iam sure i will have more questions but i cant find any info about this online so I was wondering if anyone here knows if its ok to feed Uros:

nori, its dried roasted seaweed they use to wrap sushi in, I think it has a fairly high amount of salt but its supose to have a lot of vitamins etc in it,
dried or fresh mushrooms
flowers from apple or cherry trees,