qustion about rac appy one-off patch and patchset

our customer have some  qustion about rac appy   one-off patch  and patchset ?

db is oracle 11g rac db (two node), they want update rac from 11.1.0.6 to 11.1.0.7

1.when update crs from 11.1.0.6 to 11.1.0.7, we see first need to shutdown crs damon, so my quesiton is

when  use oui update crs ,how oui kown there is two node rac , i guess it get the information (two node rac) from orainventory,

so update two node at a time, is my right?

2.when  update db from 11.1.0.6 to 11.1.0.7, does we need to shutdown crs damon or just shutdown instance ?

why ?

3.when  update db  to apply a one-off db patch ,    does we need to shutdown crs damon or just shutdown instance ?