Welcome to the forum and thank you for purchasing Yummy FTP!
I understand that quite few people are using Yummy FTP as an FTP backup utility, so it's a popular use of the software. I'm glad to hear you find it useful too

1. Yes, better logging is on my To Do list
2. Pausing transfers and syncs, including scheduled ones, is in the latest beta build
3. Something which has been raised before. There are existing ways of doing this, such as cron jobs, and other scheduling applications, but I would like to make it built into Yummy FTP at some point.
4. No, I think Yummy FTP should remain focused on Internet file transfer. HD backups is something best left to apps that specialize in that sort of thing.
5. Could be an idea... though I seem to recall that the Cute FTP makers had something similar, albeit not with the unattended backup feature you're suggesting.
Thanks for the feedback!