I think both approaches are valid but I think the extra weight and risk on the chain of RC pools make me lean towards implementing direct RC delegations with posting auth (even though I'll have to redo everything haha) along with a tool for people to "trail" other people's delegations. The UX benefits are also non negligible.

100% agree. Pools could be added later if we really want oversubscription.

About RC faucets, it would be really convenient if users could delegate their RC to one account, and then that account could become a faucet for all of hive. It could even charge a small fee for RC delegations, giving a return back to the RC delegators. But this requires the ability to delegate delegated RCs, which you said introduces too many edge cases.

Any other way to achieve that? Maybe create a special account on the chain acting as a fee based RC pool?