Don’t know if there’s one for RW8, but here’s something on RW7
https://help.realmacsoftware.com/en/articles/1905460-how-to-uninstall-rapidweaver
Without knowing what problems you are having it’s difficult to say what’s going on. For most problems that a reinstall might help with, just reinstalling a fresh copy of the app into the applications folder does the trick.
As for addons, some problems are caused by old or corrupt addons, so if you are going through the process of reinstalling might consider reinstalling Them as well.
I personally use an open source program called app trap. Just move the app to the trash and it gives you an option to delete the system files that go with it.