I see some inbound connections that have IPv4 addresses. These IPv4 addresses do not show up on bitnodes, so I am a bit curious as to what these addresses are.
Likely node that do not accept incoming connections. They do not show up on bitnodes because bitnodes cannot connect to them through the crawlers. Can also be due to the other reasons I outlined in the other thread as well.
Is my node running both on IP and TOR?
You are only connecting to onion addresses through the proxy because you specified oniononly. However, the reason why you're seeing IPV4 nodes is because you didn't bind your node to your Tor instance. As such, peers are still able to connect to you because you are still listening on your local IPV4 address. To prevent this, add bind=127.0.0.1.
If I understand correctly when running a node on TOR, DNS seeders are not utilized and it defaults to the harcoded list of .onion addresses. My first outbound peer was not in the list of addresses in the file. Where could this have come from?
Connections do not necessarily have to be maintained after connections. The primary and intended purpose of your seeds is to establish an initial point of contact to the network and your peers will populate and allow you to connect and get to know other peers.