Nuclear is not a good choice because it would take decades to even agree that they need to be build and then decades more to actually build them. That makes it a pretty horrible option to fill any gaps. We can fix most of the issues you mention during that timespan. Honestly, it just requires applying economies of scale to what we have right now to drop the cost and make it even more cheaper than it already is.

I expect more nuclear to be shut down than being delivered during that time. It's not a growth market.

20-30 years from now, several countries are planning to be 100% on renewables and most of those are not planning to build any new nuclear plants. Most of the remaining countries will be making similar plans in the next ten years.