Im gonna be honest i did not read the whole thing you posted, but i believe there are massive MASSIVE design issues with odyssey as it currently stands.
Odyssey right now, is so dethatched from the rest of the ED game, that at current state its nothing more then a bolt on FPS experience, i would not even call this an expansion, its more of a DLC add on.
What i mean by dethatched is that, none of the activates that take place in odyssey effect the rest of ED at large. Its complexly encapsulated in itself and thats the problem. Anything i do on foot, any progress i make on foot, servers to only make more progress on foot. There is nothing i need to gather, find, farm, research ect ect on foot that would then end up changing or making new game play for space. Anything i do with my ship, effects nothing for the on ground experience, and thats the problem.
If i completely ignored the odyssey content, i would not miss out on anything else elite has to offer, it does not further the experience.
Horizons how ever did do this well. I had a real reason to get out into the SRV, because it offered me things i could then use to upgrade my ship, to further my game play experience with in ED. That to me is the biggest issue odyssey has, aside from performance issues.