OMV doesn't get "stuck" when removing configurations, I've found that the creation process must be done in reverse order. In your case it would be:
1. Delete Samba/CIF shares
2. Delete the Shared folders
3. Unmount and Delete the file system
4. Delete the RAID array
4.1 And to be sure, go under Storage, S.M.A.R.T, Devices, and turn monitoring off for the physical disk(s) you want to delete. Delete all schedule tests, if any.
After that's done, under the Settings Tab, you could turn S.M.A.R.T off completely.
5. Delete the physical disks