Hi Travis
A send to Sampler / Designer or any other app counts as one download. It's a way to save time (download and open the file automatically), not a way to preview the susbtance file.
And the 100Gb of storage with 30 days of versioning is an access to the Adobe Cloud in order to store your files, and 30 days of versioning means that you can have access to all the versions of your file during 30 days, so if you have a file stored on the Adobe cloud and modified several times in the last 30 days, you can retrieve all the different versions of the file (useful if you did an unintended modification on a file, or if you accidentally delete a file)
Nico