If the p2p is ok, there also can proxy the real ip by a proxy ip.
The bt system also work without dns. Every bt client has a list. If you want to find someone, you can ask the clients in your list for help. The clients in you list, will send you some items from his list to help you to find it.
These list help the bt system become decentralization.
The TLS problem is also ok. If a relay has a pubkey, it also own a private key. Clients and relays can exchange a encrypt key with private key. This action is just like How TLS work.