This looks like a massive amount of effort. I commend you for even trying, but would caution that only very few people will be able to take part in this.
At the same time, it’s lacking a clear use case. Maybe we don’t need all of that in the first shot. Without a use case, we don’t know. Without a use case we don’t have requirements. So, maybe starting with step 11 would be an idea 
FWIW, I quite liked ROS1’s “just have a real-time capable publisher” approach. It’s, by far, not enough in the long run, but it did get us into the kinds of system we were interested in. It’s also a very modular approach, because it essentially by-passed the “normal” core.
As for the regular ROS2 core, I would love to see some analysis. Maybe we could convert some of your goals into code analyzer rules, and then run it over the code-base to see how many problems there are and where they are located (yes, all of us who have looked know there are quite a few, but it always helps to have some numbers to get a better grasp of the issue).
For the record, in the micro-ROS effort, we are currently targeting Cortex-M class micro-controllers with a POSIX RTOS (NuttX). Reference platforms are mostly single core.
Next week are Easter holidays for many people.