Chopin does love that sort of nonsense. It shows up time and time again. Ideally, of course, the sixteenth ornamentation would be lovingly and flowingly played so that it just happened come out even with the steady pulse of the eighth notes. Given time -- and a lot of practice and a certain level of genius, and the moon and planets aligned just so, that might happen.In the meantime, what you are suggesting will work quite nicely, thank you. At least I hope it will; it's what I do with things like those passages... What is essential is to keep the overall pulse going evenly.
I think Chopin had a quite specific purpose in these figures. They are normally just one more or one less than what would be a straightforward alignment. If it were straightforward, certain of the notes would be accented - by being just that one off, no note, bar the first, falls on an accent, so the whole thing has a brief independence from the pulse.
Hope it helps
No. The bass line should be in strict time, but the RH is free to flow. Counting won't get you there.
Try more nocturnes.