Thank you, mostly cleared up. Re. my Dropbox question, I heard somewhere that if I store my encrypted wallet on Dropbox that even if your wallet file was encrypted, somehow because of the nature of Dropbox they will be able to easily break your encryption routine. Don't know why that would be.
Anyways, let's just say I don't ever completely synchronize with the network (e.g., lets say because I power down the comp. 8 hours per day), does that mean I can't properly use Bitcoin or I just lose some level of functionality?
Finally, I'm one of those MacOS losers (currently on a MacBook 10.6.
. My plan is to eventually start storing and using Bitcoins on this computer, have a strongly encrypted online wallet backup and a strongly encrypted USB backup that I store in a safe.
Should I have Bitcoin-QT running on the MacBook that I use frequently (I'm online a lot) or should I invest some time and energy to have Bitcoin-Qt loaded on a bootable USB, for security reasons? As long as the laptop itself is secure (e.g., locked in a house and password protected, and running behind a firewalled router), that sounds like a reasonable setup, right? Would I need to go to a bootable USB for maximum security? Opinions?
What I'm trying to do is, obviously, have a Bitcoin "bank" running that's secure and within the confines of my current setup (e.g., I essentially just have one computer and a jailbroken iPod touch - and I don't want to use Blockchain for anything, BTW).
Thanks again.