Great write up! First, I want to point out, as you probably know but didn't mention, that hidden services can be multihomed, you simply publish the descriptor from two or more boxes. It isn't common, but I have talked to people who do it. Also, I2P has a hidden mode that is similar to entry guards and Freenet's darknet mode. So the features of Tor and I2P overlap more than is usually considered. One of the most important properties of an anonymity network is the size of the user base. A high latency mix network with one user offers no anonymity. Similarly, I would feel a lot safer using I2P if it had a million concurrent users. Unfortunately, it only has 10,000 to 20,000 users. The main reason of course is that Tor offers easier access to clearnet sites, and it doesn't require you to be a relay. So those are the most important properties for an anonymity network with a large user base. But to address your ideas, are you brainstorming a theoretical network, or something actually worth building? Because I think any competitor network will suffer the same problem that competitor darknet markets suffer. Everyone is on SR, so everyone will use SR, regardless of how good the alternatives are from a technical standpoint. Right now, 90% of anonymity network users are on Tor. It's doubtful a significant number of people would bother to use another anonymity network, even if was much more robust. Tor is "good enough" for most people. So if you're describing a theoretical network, your ideas are good. If you want to build something that people would actually use, why not layer it on top of Tor? Route it through Tor but with additional properties that enhance anonymity. Since Tor clients control their circuits, they can easily build variable length paths. Adding timing delays would require modification of relays, and thus cooperation of others, but it might be easier to convince the Tor developers and relay operators to do that than to build a useful competitor network.