Yes
This is a managed service.
CCX supports multiple AZs if the Cloud Provider does.
Yes, but the write-only instances is read-write. It allows both reads and writes.
Does support use a Proxy or Load Balancer (fora example, if there are 2 or more Read Replica instances, then Read can be load balanced across multiple instances).
DNS is used to facilitate this. However, the user can create his own loadbalancer (such as HAProxy or ProxySQL) and connect to the database service. A load balancer should be placed as close as possible to the user's application. We recommend that the end-user manages the loadbalancer.
Yes, backups are created automatically. The user can set the frequency.
Only minor upgrades. Major upgrades are not supported in an online operation. See product documentation about upgrades (Life-cycle management)
Yes. See product documentation.
See product documentation.