Great list! Here's some more. No doubt some overlap with some that you've mentioned, but deserve individual attention.
1. Tradable bounties, like the social policy bond system (https://socialgoals.com/).
2. Lotteries. Every zap goes into a pool that pays out users daily / monthly. Developer gets a percentage.
3. Service Level Agreements / Retainers. Pay a fee, get prioritized customer support.
4. Build a Monero miner into the client. Share all mining proceeds with p2pool. Developer gets a percentage.
5. Fines / virtual swear jar.
6. Escrow services.
7. Dispute resolution (e.g. Kleros)
8. Loss leader for consulting services.
9. Retroactive public goods funding. (https://tea.xyz, https://vitalik.ca/general/2021/11/16/retro1.html)
10. Venture capital (help users to start businesses of their own, take a percentage)
11. Token sales + dev tax / founders reward (https://z.cash)
12. Bridging services - send / receive nostr posts to legacy services (Twitter / Facebook, Instagram) for a fee
13. Identity vetting / management (BrightID, STAMP Protocol)
14. Rugpulls. :)
15. Contract enforcement. Require performance bonds from members which are forfeit if they don't fulfill contracts with other members.
16. BAT token (Brave browser rewards)
17. Incentivized forking (https://scribe.rip/@arweave/arweave-is-an-evolutionary-protocol-e072f5e69eaa)