no need to fear...
as long as you have backups all is good.
DrivePool does not use encryption by default. no 'encryption keys' exist so no worries there. it is a non-issue.
CloudDrive provides encryption, but if you are not using it, there is no need to even consider it in this discussion.
refering to my initial reply:
step 1. for your convenience. nothing else.
step 2. DUH!
step 3. is an all-around good idea. self-explanatory.
step 4. this is the best practice. mostly just to ensure no screw-ups. no 'real need' to do so. if you are confident you know which drive to re-install to... go for it. if you manually format your C:\ drive (or when asked during installation process) make sure you choose GPT partition (should be selected by default).
step 5. self-explanatory.
step 6. self-explanatory.
step 7. self-explanatory.
step 8. if you care, reset your settings the way you had them before the reinstall. if you are good with the default settings, don't worry about it. a REBOOT is a good idea here.
step 9. anytime you reinstall/reset/change settings etc. in DrivePool, it is best practice to remeasure after you save changes. if you go with the default settings, it will probably remeasure all by itself upon reboot. if not... Manage Pool ^ Remeasure > Remeasure.
very simple procedure actually. nothing to fear