1- It does not maintain the configuration synchronization in this way. When the failover pair is first powered up, a synchronization occurs. Beyond that, commands entered on the primary unit are passed to the standby unit in real time. Subsequent "wr mem" commands on the primary unit are replicated to the standby unit thus saving the config on the standby unit. If for some reason you wish to write the config to the standby you can issue the "wr standby" command. This will not, however, save the config to nvram.
2 - No.
3 - I assume you are referring to stateful failover. This is done in real time else the failover could not be stateful.
We have configured the outside and inside Interface with official ipv6 adresses, set a default route on outside Interface to our router, we also have definied a rule , which also gets hits, to permit tcp from inside Interface to any6.
In Syslog I also se...