If everyone has a relay, then you just connect to 100 people you like. Aggregate 100 connections into messages, and display. Easy search and file sharing. All replays are also stealth tor nodes. 

It will be too complicated for 95% of users. So a good test like cicada.  

 Doesn't sound good. I'd keep the relay functionality separate from Tor node functionality. The most integration they might need is a relay where the network interface it relies on is Tor (which is definitely one of the first relays that should be made under my model) 

 It must be mandatory to prevent people from using DNS, so they get used to an onion hash to talk to your relay. Even with 20 people, it will be a very fun app. Wild west.  

 Let the military industrial complex prevent the use of DNS themselves, no need to self-censor.