I am facing the following issues while setting up alwayson.

1) Not able to set the listener to the alwayson group. Error--

The WSFC cluster could not bring the Network Name resource with DNS name 'MyAGListener' online. The DNS name may have been taken or have a conflict with existing name services, or the WSFC cluster service may not be running or may be inaccessible. Use a different DNS name to resolve name conflicts, or check the WSFC cluster log for more information.

The attempt to create the network name and IP address for the listener failed. The WSFC service may not be running or may be inaccessible in its current state, or the values provided for the network name and IP address may be incorrect. Check the state of the WSFC cluster and validate the network name and IP address with the network administrator. (Microsoft SQL Server, Error: 19471)

2) Also we are planning to have 3 replicas with one server acts as principal and the other two replicas one synchronous and other asynchronous setup. We kind of planning to achieve both HA + DR by using alwayson feature. But we cannot replicate system databases. Is there any way to achive this?

3) to setup transactional replication can we use listener virtual name or it asks for physical name? If it accepts physical server name we can't go with servername as it causes issues when failover happens.

4) Also I have a table with identity column on in a database which is in alwayson group. For some reason the values jumped from 1,2,3,2002,2003? What could be the reason behind this?