1. Yes, curating the featured channels is an ongoing process and ultimately users will be able to curate channels too, beyond their main channel containing their subscriptions. (The mechanism is already in place behind the scenes as all the featured channels are owned by a single "featured" user.) If you have any specific suggestions, please list them here or mail mike@player.fm, thanks.
2. Agree - similar to YouTube's time-based URLs. For sharing a point in the podcast as well as resuming. I think it would be nice to bookmark a time range as well, for sharing/commentary purposes.
3. Definitely want to add ratings. This would be cool for a given podcast series as in iTunes, but an extra benefit here is you'd be able to see how a user rated things in their own channel too.