I can't answer all of your questions, but can answer these:
1a - yes, you can write the backup to whatever drive/partition you want. Externally, too.
Yes, you can restore from the other/external drive, whatever you've backed up.
3 - yes, create the bootable DVD and use that to restore...
Here's how I use Acronis; very basic:
* Full backup of C:\ partition. Occasionally, I'll back up my data partitions as well. Backups reside on an external drive. I use Acronis, running under Windows, so no need for boot DVD.
* For restores, I boot up the DVD via usb DVD drive, then restore from the external drive to wherever I need a partition to go. You can also do file/folder level restores if you want. For those, I usually run Acronis under Windows to grab particular file(s). I had some misc. problem a long time ago trying to do full partition restores under Windows, so that's why I boot up the DVD to restore those. Also, when restoring, I tick the box about 'recovering disk signature'.
That's all I do, but works for me