First of all, thanks for your words 🙂 So sad you need to remove ATUM.
Well, to do this properly you have to take two things into account:
If you are not going to use ATUM anymore and want to remove all the data from the database, you should activate the 'Delete data when unistalling' option in ATUM Settings > General.
If you want to keep ATUM data (as purchase price, for example), you have to make sure that the 'Delete data when unistalling' option is deactivated.
With the second option nothing is going to be removed, but you won't be able to access to ATUM data until you install it again.
However, we just remove ATUM data, never Woocommerce data.
Hope this helps,