1, 2, 3. Port 8333 is correct regardless of pruned or not. 8333 is the default port, but in some cases (such as multiple nodes on the same local network), you might want to change it.
4. A pruned node only saves block information relevant to your wallet.
5. Full nodes provide block and transaction data to other full nodes. I don't know specifically how being a pruned node affects the amount of outgoing data, but I imagine it reduces the amount significantly because you don't store the entire block chain.

For bitnodes, did you enter your local IP address, 192,168.x.x or 10.x.x.x, or did you enter the address for your local network?