There is debate as to whether you are or are not a Full Node if you are not receiving incoming traffic. In my view, you are not an optimized Full Node if your incoming traffic is zero. But what I don't understand is this: What is the degree of support of consensus mechanism given Full Node with versus without incoming traffic? Anyone?
There is no debate and if you’re validating consensus rules fully, then you’re a full node. The difference between allowing incoming connections and outgoing connections is only if peers can connect to you instead of solely connecting to other peers.
Connections are bidirectional and hence you’re relaying transactions and blocks similarly in both directions. There is no difference otherwise.