Good questions!

1.) There is a substrate, but they are two layers of complex systems (and emergent behavior) removed from it. Neuronal connections are biological, they generate consciousness (for simplicity, let's consider it "what we perceive") and then on top of that live memebionts. You can always go all the way down to biology and physics (and up to hypergraphs if you will:), but the fact that it is an emergent property of a complex system (which is an emergent property of another complex system, and waayy down) makes it distinct imho.

Memebionts are not consciousness that runs on neurons, it is a form of life that runs on many conscious beings forming culture (one way up).

2.) Producing energy - if it is captivating enough for the consciousness to spend energy making it spread and alive. Religions, at least the ones that survived, are quite metabolically efficient - they cause the lower layer of the complex system to go to churches and temples and people spend time with the memebionts, spreading it, making it grow, making use of the substrate quite efficiently. "My" random idea that I told a friend is a memebiont that does not have a good metabolism, it caused only one person (me) to spread it and then it did not metabolize enough energy to spread, or to even live in the other person's head.