This does to address directly the second problem. It does however by sacrificing flexibility. I might need to change a cell just to test a new thing (without affecting the other cells) but thats a trade off if you focus on reproducibility.
I know that requirements.txt is the standard solution to the other problem. But generating and using it is annoying. The command pio freeze will list all the packages in bloated way (there is better ways) but I always hoped to find a notebook system that will integrate this information natively and have a way to embed that into a notebook in a form that I can share with other people. Unfortunately I can't see support for something in any of the available solutions (at least up to my knowledge).