Regarding #1, see the asadmin create-service command. This can be used
to have instances started automatically after an operating system boot.
A service must be created for each instance.
I assume that by "validate-cluster" you mean validate-multicast, as
there isn't any validate-cluster command. Did you run validate-multicast
on each of the 3 hosts at the same time? Does list-instances show that
all of the instances are running? Are you using an IPv6-only system?
Tom