Is there some detailed Cloud documentation I haven't found?

I'm looking for answers to a number of questions that surely are covered in some documentation on how the cloud backups work ... not really how to do backups, but rather how to best work within Comcast's new limitations on bandwidth consumption and cloud data maintenance (IE: cleaning obsolete files).

The answer is probably a pointer to some document, which hopefully exists, the questions themselves are so far the following:
1. During cloud backups/recoveries is the data (or can it be) compressed thereby using less of Comcast's new limited data transfer per month.
2. Detailed examples of the different backup types (incremental, etc) and the data transfers required once the initial full backup transfer is completed. EG: for incremental, I presume that files are not copied when no changes, and that only portions of the files are transferred when they are changed, but how about the process of determining if a file has changed? Does it jump out to the cloud each time to determine details about the last backup of that file? Or does it keep local logs that avoid those unnecessary data transfers just considering if a backup is needed?
3. Also, slightly off the data usage topic, but something I simply have not found discussed is how to browse my data sitting out in my 50G space to see if I can clean things up. FOR INSTANCE, I deleted a cloud backup locally - did that then delete all of the backup files from my cloud space for that defined backup? I don't know because I haven't found how to browse.

I would much appreciate some pointers on getting beyond all of the how-to-do-a-backup documentation and finding some under the cover discussions that would clear up some of those questions.

THANKS!