unclear about some usage issues

[camner]

Pardon me if these are obvious, but I was not clear about them after reading the help stuff...

1. The help talks about using SD to create "checkpoints". Do I presume correctly that the way to do this is to get SD to create a complete image of my main drive whenever I want to create a checkpoint from which I could restore whenever I wish?

2. I have a second internal drive I use for a daily backup of important folders (Documents, Desktop), but I start with a clone so I can boot from it if needed. Can I use SD for this daily partial backup? If so, I presume I have to write a custom script, right? Can that custom script be set for a "smart" backup? But see #5 for confusion about the suitability of this.

3. The docs indicate that an image backup is the "best" backup (vs a folder backup). Does that suggest that folder backups are most suitable for moving systems around, and that otherwise they aren't so useful?

4. Why isn't there a way (or is there) to create an image without actually creating a clone first? Wouldn't that be an effective way of creating "checkpoints" without having to create a folder by folder clone at the same time?

5. The help files state: "Do not use Smart Update to selectively copy files to or from a clone:" This confuses me. What is the point of Smart Update if it isn't to selectivey copy files from one's main drive to a backup drive (internal or external) that one first created via the cloning process?

Thanks...