My guess is that you’re think far too deep.
I recommend you just jump in and convert one or more of your projects. The only caution is that you of course should have a decent backup strategy in place.
Secondary tip is that the first (few) time(s) you do the conversion, it’s just for practice. Get a feel for how it works, toy a bit around with the results. If you make big mistakes, just do it over, if you encounter some serious problems, post them on the forum. If it “mostly works”, then change the status of the conversion from “experimental” to “working”, and then do the next project.
The eagle importer has been working for quite a few years now, and sure, there are issues, but it works pretty well. The author of the Rosco-M68k project once mentioned on hackaday that he was curious about KiCad, and I reacted to that by doing the initial project conversion to KiCad for him. That was in the beginning of 2020.
In 2022 you already wrote:
There is also a difference of what your goals are. Do you just want to do a “one to one” conversion, or do you want to convert it to a fully native KiCad project to the point that remnants of the eagle history are erased? (Such as replacing the imported resistors / capacitors with KiCad’s native versions).