1) Onto your USB HD you mentioned. As is 2) so that you can 3) boot to it.
4) You could, but I did it to the same USB HD. So I now have a bootable copy of my existing mini on an external USB HD. It also has a .img file (backup) of my mini on it. I did this because I'll restore/backup to the .img file from now on and leave the install on the USB HD alone, except for adding some utility programs (DiskWarrior, etc.) to it or adding files I'm transferring or DVD .iso's or anything else. But I'll have the .img to fall back on when I need it.
5) Yes, use your imaged OS Install disc that you created on the USB stick (or another USB HD if you don't have a flash drive) with netbookMaker
6) Yup, make yourself a rescue drive based off your current, working OS X install and toss the CCC'd .img backup file on it.
7) let me list the boots and what you do with each:
A) Boot off your existing mini partition. Backup to the USB HD with CCC as files. Run NBI from your mini partition and 'bless' your USB drive to make it bootable. Also make your USB OS X flash drive with NBM if you haven't already.
B) Boot off the USB HD and use CCC to backup your mini partition to a .img file. You could probably do this from the A) boot and save a boot step. I just did this because I like backing up from a drive that isn't the current live OS.
C) Boot off the USB flash OS X Install drive. Use disk utility from the Utility menu to erase the mini OS X partition and then install OS X, onto the newly erased mini partition.
D) Boot onto the newly installed mini partition just to make sure you can. This will verify you got Chameleon installed correctly.
E) Boot off the USB HD. Disk Utility and again erase the mini OS X partition. CCC restore from the .img file in the USB HD to the mini partition. Run NBI from the USB HD and apply it to the mini partition.
F) Boot onto your now restored, working, ready for dual boot with hybrid GUID/MBR partitioning OS X mini partition.
Mini1: Vostro A90, Black, 2G, 1.3 Webcam, Bluetooth, 64G SuperTalent, OS X 10.6.4
Mini2: Mini9, Black, 2G, 0.3 Webcam, Bluetooth, 32G RunCore, OS X/Win 7, internal PCI-e SHDC Reader
Mini3: Mini10v. Black, 2G, Webcam, 640G HD, OS X 10.5.8/Win 7/Ubuntu [Hibernate w/NBI 0.8.3 RC4] Dropbox Referral