A full traceback would help us to help you.
Yes that is true. See my version pins here Bda.plone.shop development focus/direction? - #26 by petschki to get the current working package versions for Plone 6.
Unfortunately not. These are the only hints I've found in the docs Contribute to Plone 6 core — Plone Documentation v6 ... feel free to add your experience there.