1. What happens if the government requests access to the servers and the enabling of logs as a matter of national security?
2. It seems like you're simply going to store 1,000 of the latest messages on your server. In a less active chat room could be weeks worth of history.
In short, you're claiming privacy is your selling feature. However, it doesn't seem very secure, so it's not going to appeal to people that are serious about security. As for casual people, if I'm a Discord user, does this sound like a great sales pitch?
1. Private messaging is removed.
2. Chat history is reduced to minutes or weeks depending on room activity.
3. I need to pay for sharing images or voice.
I think you'll struggle with this concept. If you said your goal was to make ephemeral chat rooms, so people could be more carefree with their messages, I could understand the selling point. But, instead you're talking about a watered down Discord in exchange for some security theater. I don't see the appeal for anyone there.
Lastly, let's say I'm wrong and you do start gaining traction and you're on to something. What prevents Discord from adding that same feature, and giving chat room owners the ability to limit history? How do you compete?